Digital PDFs

EK-0RM05-SV-2

December 1988

294 pages

Original

11MB

Document:	RM05 Disk Subsystem Service Manual
Order Number:	EK-0RM05-SV
Revision:	2
Pages:	294
Original Filename:

OCR Text

EK-ORMOS-SV-o02

RM05 Disk Subsystem
Service Manual
Portions Of This Document Reprinted
. With Permission Of Control Data Corporation

Digital Equipment Corporation • Colorado Springs, Colorado

First Edition, December 1980
Second Edition, April 1982
Copyright

1982 by Digital Equipment Corporation
All Rights Reserved

The material in this manual is for informational purposes and is
subject to change without notice.
Digital Equipment Corporation assumes no responsibility for
errors which may appear in this manual.

any

Printed in U.S.A.
This document was set on DIGITAL's DECset-8008 computerized
typesetting systea.
o

Class A Co.puting Devices:

Notice: This equipment generates, uses, and may emit radio
frequency energy. The equipment has been type tested and found to
comply with the limits for a Class A computing device pursuant to
Subpart J of Part 15 of FCC Rules, which are designed to provide
reasonable protection against such radio frequency interference
when operated in· a commercial environment.
Operation of this
equipment in a residential area may cause interference in which
case the user at his own expense may be required to take measures
to correct the interference.
The following are trademarks of
Maynard, Massachusetts:
DEC
DECUS
DIGITAL
Dig i tal Logo
PDP
UNIBUS
VAX

Digital

DECnet
DECsystem-10
DECSYSTEM-20
DECwriter
DIeOL
EduSystem
lAS
MASSBUS

Equipm~nt

Corporation,

OMNIBUS
OS/8
PDT
RSTS
RSX
VMS
VT

CONTENTS
CHAPTER 1

GENERAL INPORMATION

1.1
1.1.1
1.1.2
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10

INTRODUCTION ••••••••••••••••••••••••••••••••••••••• 1-1
Scope of Manual •••••••••••••••••••••••••••••••••• l-1
RM05 Hardware Maintenance Plan ••••••••••••••••••• l-1
DESCRIPTION •••••••••••••••••••••••••••••••••••••••• l-l
DISK PACK •••••••••••••••••••••••••••••••••••••••••• 1-6
SUBSYSTEM FEATURES AND CAPABILITIES •••••••••••••••• 1-6
REFERENCE DOCUMENTATION •••••••••••••••••••••••••••• 1-8
SUBSYSTEM CONFIGURATION •••••••••••••••••••••••••••• 1-8
DUAL-PORT CONFIGURATION RESTRICTIONS •••••••••••••• l-ll
SUBSYSTEM SPECIFICATIONS •••••••••••••••••••••••••• 1-11
NON-VDE/VOE RM05 SUBASSEMBLIES •••••••••••••••••••• 1-15
RM ADAPTER SUBASSEMBLIES •••••••••••••••••••••••••• 1-18

CHAPTER 2

INSTALLATION AND CHECKOUT PROCEDURES

2.1
2.2
2.3
2.3.1
2.3.2
2.3.3
2.4
2.4.1
2.4.2
2.4.3
2.4.3.1
2.4.3.2
2.4.3.3
2.4.4
2.4.5
2.4.6
2.4.7
2.4.7.1
2.4.7.2

INTRODUCTION •••••••• ~ ••••••••• ~ •••••••••••••••••••• 2-1
SITE PREPARATION AND PLANNING •••••••••••••••••••••• 2-1
UNPACKING THE DRIVE •••••••••••••••••••••••••••••••• 2-4
. Unpacking the Drive Cabinet .......... ·••••••••••••• 2-4
Unpacking RM Adapter Cabinet ...................... 2-9
Unpacking RM Adapter ••••••••••••••••••••••••••••• 2-9
DRIVE INSTALLATION PROCEDURES ••••••••••••••••••••• 2-10
Preinstallation Inspection •••••••••••••••••••••• 2-10

2.4.7.3
2.4.7.4
2.4.7.5
2.4.7.6
2.4.8
2.4.8.1
2.4.8.2
2.4.8.3
2.4.8.4
2.4.8.5
2.4.8.6
2.4.9

Page

,Daisy-Chain·Groundin9···~·······················2-11

AC Power Wiring ••••••••••••••••••••••••••••••••• 2-12
VDE 50Hz To 60Hz Conversion ••••••••••••••••••• 2-12
Required Parts •••••••••••••••••••••••••••••••• 2-15
Conversion Procedure •••••••••••••••••••••••••• 2-15
Drive Power Cable Routin9 •••••••• ~ •••••••••••••• 2-16
I/O Cable Installations ••••••••••••••••••••••••• 2-18
Logical Address Plug Installation ••••••••••••••• 2-20
RM Adapter Cabling •••••••••••••••••••••••••••••• 2-20
Adapter AC Power Cable Routing •••••••••••••••• 2-21
MASSBUS and Power Sequence Cable
Installation •••••••••••••••••••••••••••••••••• 2-23
Cable A (6~ Position) lnstallation •••••••••••• 2-24
Cable B (26 Position) Insta1lation •••••••••••• 2-26
Frame Grounding Procedure ••••••••••••••••••••• 2-26
Final Securing of Adapter Cabinet ••••••••••••• 2-26
Cabling Procedure for Second RM Adapter ••••••••• 2-28
Adapter AC Power Cable Routing •••••••••••••••• 2-29
MASSBUS and Power Sequence Cable
Installation •••••••••••••••••••••••••••••••••• 2-30
Cable A (60 Position) Installation •••••••••••• 2-31
Cable B (26 Position) Installation •••••••••••• 2-31
Frame Grounding Procedure ••••••••••••••••••••• 2-34
Final Secur ing of Adapter Cabinet ••••· ••••••••• 2-34
Dual-Port Option (Lower RM Adapter) •••••••.••••• 2-35
111

CONTENTS (Cont)
CHAPTER 2

INSTALLATION AND CHECKOUT PROCEDURES (Cont)

2.4.19
2.4.11
2.5
2.5.1
2.5.2
2.5.2.1
2.5.2.2
2.5.3
2.5.3.1
2.5.3.2
2.5.3.3
2.5.3.4
2.5.3.5

2.6.2
2.6.2.1
2.6.2.2
2.6.2.3
2.6.2.4
2.6.3

Dual-Port Option (Upper RM Adapter) ••••••••••••• 2-40
Cabinet Leveling •••••••••••••••••••••••••••••••• 2-45
INITIAL CHECKOUT AND START-UP ••••••••••••••••••••• 2-46
Drive Power Up •••••••••••••••••••••••••••••••••• 2-46
Tests and Adjustments ••••••••••••••••••••••••••• 2-47
Testing With Software ••••••••••••••••••••••••• 2-47
Preliminary Setup ••••••••••••••••••••••••••••• 2-47
Head Alignment Procedure •••••••••••••••••••••••• 2-51
Installation of Head Alignment Card ••••••••••• 2-51
Preliminaries for Head Check or A1ignment ••••• 2-54
Initial Setup •.•••••••••••••••••••••••••••••••• 2-56
Servo Head Alignment Check •••••••••••••••••••• 2-56
Read/Write Heads Alignment Check and
Adjustment •••••••••••••••••••••••••••••••••••• 2-59
Servo Syste~ Tests and Adjustments •••••••••••••• 2-61
Operating Procedures •••••••••••••••••••••••••••• 2-66
Continuous Seek, No Read/Write •••••••••••••••• 2-67
Random Seek, No Read/Write •••••••••••••••••••• 2-67
Write-Format •••••••••••••••••••••••••••••••••• 2-68
Read •••••••••••••••••••••••••••••••••••••••••• 2-72
Write Flag.................................... 2 - 7 3
Check Data-Error Logic •••••••••••••••••••••••• 2-74
Trouble Analysis •••••••••••••••••••••••••••••• 2-75
Preparation of Drive for Return to On-Line
After Testing ••••••••••••••••••••••••••••••••••• 2-76
FIELD ACCEPTANCE PROCEDURE •••••••••••••••••••••••• 2-77
Introduction •••••••••••••••••••••••••••••••••••• 2-77
Error Definitions and Rates ••••••••••••••••••••• 2-77
Hard Errors •••••••••••••••••••••• ; •••••••••••• 2-78
Soft Errors ••••••••••••••••••••••••••••••••••• 2-78
Pack-Attributable Errors •••••••••••••••••••••• 2-79
Seek Errors ••••••••••••••••••••••••••••••••••• 2~79
Field Acceptance Test Diagnostic Programs ••••••• 2-79

CHAPTER 3

MAINTENANCE

3.1
3.2
3.3
3.4
3.4.1
3.4.2
3.5
3.6
3.6.1
3.6.2
3.6.3

GENERAL MAINTENANCE •••••••••••••••••••••••••••••••• 3-1
SAFETY PRECAUTIONS ••••••••••••••••••••••••••••••••• 3-2
MAINTENANCE TOOLS AND MATERIALS •••••••••••••••••••• 3-3
DISK PACK •••••••••••••••••••••••.••••••••••••••••••• 3- 4
Disk Pack Handling ••••••••••••••••••••••••••••••• 3-4
Disk Pack Inspection and Cleaning •••••••••••••••• 3-S
HEAD ALIGNMENT KIT ••••••••••••••••••••••••••••••••• 3-5
TESTING DRIVE WITH FTU OR SOFTWARE ••••••••••••••••• 3-7
Testing with the FTU ••••••••••••••••••••••••••••• 3-7
Testing with Software •••••••••••••••••••••••••••• 3-8
Preparation of Drive for Testing ••••••••••••••••• 3-8

2.5.4
2.5.5
2.5.5.1
2.5.5.2
2.5.5.3
2.5.5.4
2.5.5.5
2.5.5.-;
2.5.5.7
2.5.6
2.6
2.~.1

Page

CONTE~lTS

CHAPTER 3

3.7
3.7.1
3.7.2
3.7.2.1
3.7.2.2
3.7.3
3.7.4
3.7.5
3.7.5.1
3.7.5.2
3.8

3.P.l
3.8.2

3.8.3
3.9
3.10
3.10.1
3.10.2
3.11
3.11.1
3.11.2
3.12

3.13
3.14
3.15

3.1l:)
3.17
3.17.1
3.17.2
3.17.2.1
3.17.2.2
3.17.2.3
3.17.2.4
3.17.2.5
3.17.2.6
3.17.2.7

3.18
3.18.1
3.18.2
3.18.2.1
3.18.2.2
3.19
3.19.1
3.19.2
3.20
3.21

MAINTENANCE (Cont)

(Cont)
Page

Preparation of Drive for Return On-Line
After Testing ••••••••••••••••••••••••••••••••••• 3-10
ACCESSING THE DRIVE FOR MAINTENANCE ••••••••••••••• 3-11
Cabinet Ooors ••••••••••••••••••••••••••••••••••• 3-12
Cabinet Top Cover ••••••••••••••••••••••••••••••• 3-12
Top Cover Removal ••••••••••••••••••••••••••••• 3-12
Top Cover Replacement ••••••••••••••••••••••••• 3-12
Deck Cover •••••••••••••••••••••••••••••••••••••• 3-14
Logic Chassis ••••••••••••••••••••••••••••••••••• 3-14
Pack Access Cover ••••••••••••••••••••••••••••••• 3-14
Pack Access Cover,Removal ••••••••••••••••••••• 3-15
Pack Access Cover Replacement ••••••••••••••••• 3-16
POWER SUPPLY •••••••••••••••••••••••••••••••••••••• 3-16
NON-VDE Power Supply Access ••••••••••••••••••••• 3-16
VDE Power Supply Access ••••••••••••••••••••••••• 3-16
Motor Relay Box Assembly •••••••••••••••••••••••• 3-19
SIDE PANELS ••••••••••••••••••••••••••••••••••••••• 3-19
SHROUD AND SHROUD COVER ••••••••••••••••••••••••••• 3-19
. Shroud and Shroud Cover Removal ••••••••••••••••• 3-19
Shroud and Shroud Cover Replacement ••••••••••••• 3-21
MAINTENANCE CONTROLS AND TEST POINTS •••••••••••••• 3-22
.Maintenance Controls •••••••••••••••••••••••••••• 3-22
Test Points •••••••.~ •••.••• '............ ,••••••••••.•••• 3-23
WIREWRAP PINS •••• ~ ••..•••••.•.••••••••••••••••••••••• 3-23
CARD TEST POINTS •••• o • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 3-24
POWER SUPPLY TEST POJrNTS •••••••••••••••••••••••••• 3-25
PROCEDURE FOR MANUALLY POSITIONING CARRIAGE ••••••• 3-25
PREVENTIVE MAINTENANCE SCHEDULE ••••••••••••••••••• 3-27
TESTS AND ADJUSTMENTS ••••••••••••••••••••••••••••• 3-28
+5 Volt and -S Volt Test and Adjustment ••••••••• 3-28
Head A1ignment •••••••••••••••••••••••••••••••••• 3-28
Thermal Stabilization ••••••••••••••••••••••••• 3-30
Alignment Tool •••••••••••••••••••••••••••••••• 3-30
Carriage Locking •••••••••••••••••••••••••••••• 3-30
Initial Set-Up •••••••••••••••••••••••••••••••• 3-32
Servo Head Offset Check ••••••••••••••••••••••• 3-32
Read/Write Heads Check and Adjustment ••••••••• 3-36
Servo System Test and Adjustment •••••••••••••• 3-38
TROUBLE ANALYSIS •••••••••••••••••••••••••••••••••• 3-42
Power Supply DC Voltage Output Check •••••••••••• 3-42
Servo System Checks ••••••••••••••••••••••••••••• 3-44
Logic Controlled Servo Checks ••••••••••••••••• 3-44
Manually Controlled Servo Checks •••••••••••••• 3-61
READ/WRITE SYSTEM CHECKS •••••••••••••••••••••••••• 3-64
Write Circuit Checks •••••••••••••••••••••••••••• 3-64
. Read Circuit Checks ••••••••••••••••••••••••••••• 3-69
HEAD AMPLITUDE CHECK •••••••••••••••••••••••••••••• 3-73
MISCELLANEOUS LOGIC CHECKS •••••••••••••••••••••••• 3-74
v

CONTENTS (Cont)
CHAPTER 3
3.21.1
3.21.2

MAINTENANCE (Cont)

Page

Index Timing Check •••••••••••••••••••••••••••••• 3-74
Speed Sensor Output Check ••••••••••••••••••••••• 3-74

CHAPTER 4

REPAIR AND REPLACEMENT

4.1
4.2
'4. 3
4.4
4.5
4.6
4.6.1
4.6.2
4.7
4.7.1
4.7.2
4.8
4.9
4.10
4. 11
4.12
4.12.1
4.12.2
4.13
4.14
4.15
4.16
4. 17
4.18
4.19
4.20
4.21
4.22
4.23

INTRODUCTION ••••••••••••••••••••••••••••••••••••••• 4-1
ACTUATOR ASSEMBLY REPLACEMENT •••••••••••••••••••••• 4-1
BLOWER MOTOR REPLACEMENT •••••••••••••••••••••••••• 4-13
DRIVE BELT REPLACEMENT •••.••••••••••••••••••••••••• 4-16
DRIVE BELT ADJUSTMENT ••••••••••••••••••••••••••••• 4-18
DRIVE MOTOR REPLACEMENT ••••••••••••••••••••••••••• 4-19
Drive Motor Rep1acement ••••••••••••••••••••••••• 4-19
Brake Replacement ••••••••••••••••••••••••••••••• 4-23
HEAD-ARM ASSEMBLIES ••••••••••••••••••••••••••••••• 4-24
Head Inspection ••••••••••••••••••••••••••••••••• 4-25
Head-Arm Replacement Criteria ••••••••••••••••••• 4-26
HEAD-ARM ASSEMBLY REPLACEMENT ••••••••••••••••••••• 4-26
HEAD CAM REPLACEMENT •••••••••••••••••••••••••••••• 4-30
HEADS-LOADED SWITCH REPLACEMENT ••••••••••••••••••• 4-32
HEADS-LOADED SWITCH ADJUSTMENT •••••••••••••••••••• 4-33
LOGIC CHASSIS BACKPANEL REPAIR •••••••••••••••••••• 4-35
Wirewrap Pin Replacement •••••••••••••••••••••••• 4-35
Wirewrap Replacement •••••••••••••••••••••••••••• 4-36
OPERATOR CONTROL PANEL REPLACEMENT •••••••••••••••• 4-38
PACK ACCESS COVER SOLENOID REPLACEMENT (NON-VDE) •• 4-39
PACK ACCESS COVER SOLENOID ADJUSTMENT (NON-VDE) ••• 4-41
PACK ACCESS COVER SWITCH REPLACEMENT (NON-VDE) •••• 4-42
INTERLOCK SOLENOID AND SWITCH REPLACEMENT (VDE) ••• 4-43
PACK-ON SWITCH REPLACEMENT •••' ••••••••••••••••••••• 4-46
PACK-ON SWITCH ADJUSTMENT ••••••••••••••••••••••••• 4-46
PACK SENSOR ASSEMBLY REPLACEMENT •••••••••••••••••• 4-48
PARKING BRAKE REPLACEMENT ••••••••••••••••••••••••• 4-49
PARKING BRAKE ADJUSTMENT •••••••••••••••••••••••••• 4-51
POWER SUPPLY ASSEMBLY REPLACEMENT AND
MAINTENANCE ••••••••••••••••••••••••••••••••••••••• 4-53
Power Supply Assembly Replacement ••••••••••••••• 4-53
-ZCN (Power Amplifier) Card Replacement
( NON - VD E) • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 4- 5 7
-YEN (Capacitor Board) Replace~ent (NON-VDE) •••• 4-57
-YFN (Relay Board) Replacement (NON-VDE) ••••' •••• 4-58
Triac and Power Transistor Replacement •••••••••• 4-59
Power Supply Replacement (VDE) •••••••••••••••••• 4-60
-ZCN (Power Amplifier) Card Replacement (VDE) ••• 4-61
-FNN (Relay) Card Replacement (VDE) ••••••••••••• 4-61
-CFN (Control) Card Replacement (VDE) ••••••••••• 4-62
-CBN (Rectifier/Filter) Card Replacement (VDE) •• 4-62
MOTOR RELAY BOX ASSEMBLY REPLACEMENT (VDE) •••••••• 4-63

4.23.1
4.23.2
4.23.3
4.23.4
4.23.5
4.23.6
4.23.7
4.23.8
4.23.9
4.23.1e
4.24

Page

CONTENTS (Cont)
Page

CHAPTER 4

REPAIR AND REPLACEMENT (Cont)

4.25
4.26

READ/WRITE CHASSIS -XGN CARD REPLACEMENT •••••••••• 4-63
READ/WRITE CHASSIS -XFN (MOTHER BOARD)
REPLA.CEMENT ••••••••••••••••••••••••••••••••••••••• 4-65
SERVO PREAMP BOARD REPLACEMENT •••••••••••••••••••• 4-66
SPEED SENSOR ASSEMBLY REPLACEMENT ••••••••••••••••• 4-67
SPEED' SENSOR ASSEMBLY ADJUSTMENT •••••••••••••••••• 4-69
SPINDLE LOCKSHAFT REPLACEMENT ••••••••••••••••••••• 4-70
SPINDLE ASSEMBLY REPLACEMENT •••••••••••••••••••••• 4-73
SPINDLE TO CARRIAGE ALIGNMENT ••••••••••••••••••••• 4-75
STATIC GROUNDSPRING REPLACEMENT ••••••••••••••••••• 4-79
STATIC GROUNDSPRING ADJUSTMENT •••••••••••••••••••• 4-80
VELOCITY TRANSDUCER ASSEMBLY REPLACEMENT •••••••••• 4-81
VOICE COIL FLEX LEAD REPLACEMENT •••••••••••••••••• 4-85

4.27
4.28
4.29
4. 30
4.31
4.32
4.33
4.34
4.35
4.'36

APPENDIX A TB3A2 FIELD TEST UNIT
A. 1

A.1.1
A .1.2
A.1.3
A.2
A.2.1
.A.2.2
A. 2.3
A.2.4
A.2.5
A.3
A.3.1
A.3.2
A. 3.3
A. 3.4
A.3.5
A.4

Page

INTRODUCTION ••••••••••••••••••••••••••••••••••••••• A-l
Operating Voltage •••••••••••••••••••••••••••••••• A-l
I/OCables •••••••••••••• ~ •••••••••••••••••••••••• A-2
Head Alignment Cable ••••••••••••••••••••••••••••• A-2
MODES OF OPERATION ••••••••••••••••••••••••••••••••• A-2
Direct Seek •••••••••••••••••••••••••••••••••••••• A-2
.Continuous. Seek ••••.• '....... ' •••••• "•••••••••••••••••• A-6
Sequential Forward Seek •••••••••••••••••••••••••• A-6
Sequential Reverse Seek •••••••••••••••••••••••••• A-6
Random Seek •••••••••••• ~ ••••••••••••••••••••••••• A-6
READ/WRITE MODES ••••••••••••••••••••••••••••••••••• A-6
Write Format ••••••••••••••••••••••••••••••••••••• A-6
Wr i te ••••••••••••••
A-7
Reacl •••••••••••••••
A-7
Write Then Read •••• o • • • • • • • • • • • • • • • • • • • ~ • • • • • • • • • A-7
Off ,.•••••••••••••••
A-7
CONTROLS AND INDICATORS •••••••••••••••••••••••••••• A-7
,t • • • • • • • • • • • • • • • • • • • • • • • • • • • • •

•••••••••••••••••••••••••••••

FIGURES
Figure No.
1-1
1-1A
1,-2
1-3
1-4
2-1
2-2
2-3

Title

Page

NON-VDE Drive Subassembl1es •••••••••••••••••••••••• 1-2
VDE Drive Subassemblies •••••••••••••••••••••••••••• 1-4
RMe5P Disk Pack •••••••••••••••••••••••••••••••••••• 1-7
Single-Port Subsystem Configuration •••••••••••••••• 1-9
Dual-Port Subsystem Configuration ••••••••••••••••• 1-10
Space Requirements ••••.••••••••••••••••••••••••••••• 2-2
Installing Ramp on Pallet •••••••••••••••••••••••••• 2-5
Unpacking NON-VDE RMeS Drive ••••••••••••••••••••••• 2-7

vii

CONTENTS (Cant)
Figure No.
2-3A
2-4
2-5
2-6
2-flA
2-7
2-7A
2-8
2-9
2-10
2-11
2-12
2-13
2-14
2-15
2-16
2-17
2-18
2-19
'--20
2-21
2-22
2-23
2-24
2-25
2-26
2-27
2-28
2-29
2-30
2-31
2-32
3-1
3-2
3-3
3-4
3-5
3-~

3-7
3-8
3-9
3-10
3-11
3-12
3-13
3-14

Title

Page

Unpacking RM05 VDE •••••••••••••••••••••••••••••••• ~2-8
Grounding to Floor Grid ••••••••••••••••••••••••••• 2-ll
Daisy-Chain Grounding Connection •••••••••••••••••• 2-12
NON-VDE Transformer Input Voltages •••••••••••••••• 2-13
VDE Transformer Input Voltages •••••••••••••••••••• 2-14
NON-VDE Transformer Input Voltages •••••••••••••••• 2-17.
VDE Power Cable Routing ••••••••••••••••••••••••••.• 2-1 7
I/O Cable Routing ••••••••••••••••••••••••••••••••• 2-19
Cabling Single-Port Drive (Single Adapter) •••••••• 2-22
Adapter Card Cage ••••••••••••••••••••••••••••••••• 2-25
Cable Access Slot Cover •••••••••••••••••••••••••• -.2-27
Adapter Rail Mounting ••••••••••••••••••••••••••••• 2-28
Cabling Second Adapter in Cabinet (Single-Port) ••• 2-29
Adapter Card Cage (Upper Adapter) ••••••••••••••••• 2-32
Cable Access Slot Cover (Two Adapters) •••••••••••• 2-33
Adapter Backplane (Lower Adapter) ••••••••••••••••• 2-36
Dual-Port Switch (Single Adapter) ••••••••••••••••• 2-37
MASSBUS Cable Routing (Dual-Port, Single
Adapter) ••••• : •••••••••••••••••••••••••••••••••••• 2-39
Adapter Backplane (Upper Adapter) ••••••••••••••••• 2-41
Dual-Port Switch (Upper Adapter) •••••••••••••••••• 2-42
MASSBUS Cable Routing (Dual-Port, Two Adapters) ••• 2-44
Cabinet Leveling •••••••••••••••••••••••••••••••••• 2-45
Standard FTU to Drive I/O Connection •••••••••••••• 2-49
Head Alignment Connections •••••••••••••••••••••••• 2-52
Head Alignment Card ••••••••••••••••••••••••••••••• 2-53
Balanced Dibit Pattern •••••••••••••••••••••••••••• 2-57
Head-Arm Alignment •••••••••••••••••••••••••••••••• 2-58
Servo System Test and Adjustment -Flowchart •••••••• 2-62
Integrator Gain' Waveform •••••••••••••••••••••••••• 2-63
Fine Velocity Initial Check Waveform •••••••••••••• 2-65
Fine Velocity Gain Overshoot •••••••••••••••••••••• 2-66
Track Format •••••••••••••••••••••••••••••••••••••• 2-73
Head Alignment Kit ••••••••••••••••••••••••••••••••• 3-6
Standard I/O Connection •••••••••••••••••••••••••••• 3-9
Accessing the Drive for Maintenance ••••••••••••••• 3-ll
Top and Deck Covers ••••••••••••••••••••••••••••••• 3-l3
Logic Chassis ••••••••••••••••••••••••••••••••••••• 3-l5
Pack Access Cover ••••••••••••••••••••••••••••••••• 3~17
Power Suppl y •••••••••••••••••••••.••••••••••••••••• 3-18
Side Panel •••••••••••••••••••••••••••••••••••••••• 3-20
Shroud and Shroud Cover ••••••••••••••••••••••••••• 3-21
Maintenance Controls and Indicators ••••••••••••••• 3-22
Card Test Points •••••••••••••••••••••••••••••••••• 3-24
Power Supply Control Panel Test Points •••••••••••• 3-26
Voltage Regulator and Servo Adjustments ••••••••••• 3-29
Basic Head Alignment Check and Adjustment
Flowchart ••••••••••••••••••••••••••••••••••••••••• 3-31
viii

CONTENTS (Cont)
Figure No.
3-15
3-115
3-17
3-18
3-19
3-2e
3-21
3-22
3-23
3-24
3-25
3-2~

3-27
3-28
3-29
3-3~

3-31
3-32
3-33
3-34
3-35
3-36
3-37
4-1
4-1A
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
4-11
4-12
4-13
4-14
4-15
4-16
4-17
~-18

4-19
4-20
4-21
4-22

Title

Page

Balanced Dibit Pattern •••••••••••••••••••••••••••• 3-33
Head-Arm Alignment •••••••••••••••••••••••••••••••• 3-35
Servo System Adjustments Flowchart •••••••••••••••• 3-39
Integrator Gain Waveform •••••••••••••••••••••••••• 3-40
Fine Velocity Initial Check Waveform •••••••••••••• 3-41
Fine Velocity Gain Final Check Waveform •••••••• ~ •• 3-43
D/A Converter Output Waveform ••••••••••••••••••••• 3-45
D/A Converter Output Waveform Expanded •••••••••••• 3-46
Cylinder Pulse Switching Level Waveform ••••••••••• 3-48
Fine Enable Switching Level Waveform •••••••••••••• 3-50
On Cylinder Switching Level - Waveform 1 •••••••••• 3-53
On Cylinder Switching Level - Waveform 11 ••••••••• 3-54
Track Following Check Waveform •••••••••••••••••••• 3-55
Track Servo Amplitude Waveform •••••••••••••••••••• 3-59
Velocity Gain Uniformity Waveform ••••••••••••••••• 3-60
Write Circuits Test Points •••••••••••••••••••••••• 3-65
NRZ Write Data Input Waveform ••••••••••••••••••••• 3-66
Write Driver Input Waveform ••••••••••••••••••••••• 3-67
Write Drive .0~tputWaveform ••••••••••••••••••••••• 3-68
Read Circuits Test Points •••• ~ •••••••••••••••••••• 3-69
Analog Read Data Waveform ••••••••••••••••••••••••• 3-70
Data Latch Output Waveform ••••••••.••.•••••••••••••• 3-71
Read Data to Read Clock Timing •••••••••••••••••••• 3-72
Assembly· Locator NON-VDE ••••••••••••••••••••••••••• 4-2
Assembly Locator VDE ••••••••••••••••••••••••••••••• 4-4
Actuator Replacement ••••••••••••••••••••••••••••••• 4-6
Blower Assembly ••••••••••••••••••••••••••••••••••• 4-14
Drive Belt Replacement/Adjustment.~ ••••••••••••••• 4-18
Drive Motor and Brake Replacement ••••••••••••••••• 4-21
Typical Head-Arm Components ••••••••••••••••••••••• 4-26
Head-Arm Assembly Replacement ••••••••••••••••••••• 4-28
Head Cams ••••••••••••.••••••••••••••••••••••••••••• 4-31
Heads-Loaded Switch Replacement ••••••••••••••••••• 4-33
Heads-Loaded Switch Adjustment •••••••••••••••••••• 4-35
Wirewrap Pin Replacement •••••••••••••••••••••••••• 4-37
Operator Control Panel ·Replacement •••••••••••••••• 4-38
Pack Access Cover Solenoid Replacement/
Adjustment (NON-VDE).D •••••••••••••••••••••••••••• 4-40
Pack Access Cover Switch Replacement (NON-VDE) •••• 4-42
Interlock Assembly (VDE) •••••••••••••••••••••••••• 4-44
Pack-On Switch ReplacE~ment/Adj ustment ••••••••••••• 4-46
Pack Sensor Assembly Replacement •••••••••••••••••• 4-47
Parking Brake Replacement/Adjustment •••••••••••••• 4-50
Power Supply Assembly Location •••••••••••••••••••• 4-54
Power Supply Card Replacement ••••••••••••••••••••• 4-56
Read/Write Chassis Card Replacement ••••••••••••••• 4-63
Servo Preamp Board Replacement ••••••••••• ·••••••••• 4-66

CONTENTS (Cont)
Figure No.
4-23
4-24
4-25
4-26
4-27
4-28
4-29
4-30
A-I
A-2
A-3
A-4
A-S
A-6
A-7

Title

Page

Speed Sensor Assembly Replacement ••••••••••••••••• 4-68
Speed Sensor Assembly Adjustment •••••••••••••••••• 4-69
Spindle and Lockshaft Replacement ••••••••••••••••• 4-71
Cabinet with Pack Access and Top Covers Open •••••• 4-76
Spindle to Carriage Alignment ••••••••••••••••••••• 4-77
Static Groundspring Adjustment •••••••••••••••••••• 4-80
velocity Transducer Replacement ••••••••••••••••••• 4-82
Voice Coil Flex Lead Replacement •••••••••••••••••• 4-86
FTU Power Supply Layout •••••••••••••••••••••••••••• A-2
FTU Power Supply Wiring Diagram •••••••••••••••••••• A-3
Tester I/O Cables ••••••••••••••••••••••••••••••• ~ •• A-4
Head Alignment Connections ••••••••••••••••••••••••• A-5
TB3A2 Control Panel •••••••••••••••••••••••••••••••• A-8
Display Select Switch ••••••••••••••••••••••••••••• A-13
Track Format •••••••••••••••••••••••••••••••••• •••• A-14
TABLES

Table No.
1-1
1-2

1-3
1-4

1-5
l-!iA
2-1
~-2

2-3
2-4

3-1
3-2
3-3
3-4
4-1
A-I
A-2

Title

Page

RM0SP Pack Data Capacity ••••••••••••••••••••••••••• 1-8
Reference Documentation •••••••••••••••••••••••••••• 1-8
RM05 Specifications ••••••••••••••••••••••••••••••• l-11
RM~5P Disk Pack Speciflcations •••••••••••••••••••• 1-14
NON-VDE RM05 Subassemblies •••••••••••••••••••••••• 1-15
VDE RM05 Subassemblies •••••••••••••••••••••••••••• 1-17
Drive Power Consumption Requirements ••••••••••••••• 2-3
Head Alignment Card Switches and Indicators ••••••• 2-S3
Decision Logic Table •••••••••••••••••••••••••••••• 2-69
Error Conditions •••••••••••••••••••••••••••••••••• 2-77
Maintenance Tools and Materials •••••••••••••••••••• 3-4
Maintenance Controls and Indicators ••••••••••••••• 3-23
Preventive Maintenance Schedule ••••••••••••••••••• 3-27
Power Supply Output Checks •••••••••••••••••••••••• 3-44
Power Supply Card UsAge ••••••••••••••••••••••••••• 4-53
Plug Valid Indication ••••••••••••••••••••••••••••• A-ll
FTU Test Points ••••••••••••••••••••••••••••••••••• A-19

CHAPTER 1
GENERAL INFORMATION

1.1

INTRODUCTION

1.1.1
Scope of Manual
This manual contains information concerning the installation,
operation, and servicing of the RM0S Disk Subsystem.
It is
intended to be used by DIGITAL Field Service and customer
maintenance personnel.

1.1.2
RM0S Hardware Maintenance Plan
The primary strat1egy for maintain:lng the RM0S Disk Subsystem calls
for using on-line software and/or the Field Test Unit to isolate
problems to a field replaceable unit (FRU) on the failing option.
Once the fault is isolated, the failing 'PRU is "replaced.
The
Authorized Returns List identifies those FRUs to be returned.
1.2
DESCRIPTION
The RM05 is a vendor-built storage 'module drive (SMD) connected to
a DIGITAL RM adal)ter.
The RM05 has a formatted capacity of 256
megabytes.
The RM adapter converts MASSBUS signals from the
controller into compatible signals for the drive.
(The major
sub-assembl ies of the drive are shown in Figure 1-1 and Figure
1-1A. )

Using the appropriate MASSBUS controller, the RM05 can be used
with the PDP-11/70 and VAX-ll/780 computers •
•
The system resides in two free-stand ing cabinets.
The adapter
cabinet has provisions for a second adapter.
Thus by adding a
second drive, 'another cabinet is not required.

1-·1

Figure 1-1

NON-VDE Drive Subassemblies

1-2

Sheet 1 of 2

MAGNET

CONTROL
PANEL

PACK
ACCESS
COVER
SOLENOID

PARKING
BRAKE

BLOWER
ASSEMBLY

PACK
ON
SWITCH

SPEED
SENSOR
CZ·0390

Figure 1-1

NON-VDE Drive Subassemblies

1-3

Sheet 2 of 2

CONTROL
PANEL

CZ·0e35

Figure 1-1A

VDE Drive Subassemblies

1-4

Sheet 1 of 2

MAGNET

LOGIC
CONTROL
PANEL

PACK
ACCESS
COVER
SOLENOID

PARKING
BRAKE

PACK
ON
SWITCH

Figure 1-1A

SPEIED
SENSOR

VDE Drive Subassemblies

1-5

Sheet 2 of 2

The RM05 has a VDE and NON-VDE version.
The difference between
the two will be called out in this manual where appl icable.
The
major VOE differences are the following.
o

Redesigned power suppl y

Motor relay box between power supply and drive motor

Motor assembly with direct drive brake

Improved pack access cover interlock

Logic chassis hinge is changed to provide clearance for
the repositioned power supply

1.3
DISK PACK
The RM05 uses' a 14 inch diameter (RM05-P type) removable disk pack
which has 12 platters (see Figure 1-2).
The top and bottom
platters are used. to protect the ten inner platters.
Of the 20
surfaces on the ten inner platters, 19 are used for data storage
and one is used for servo data.
Table 1-1 gives RM05P Disk Pack
specifications.
Operator and user information and detailed
specifications on both the media and the drive can be found in
Chapter 1 of the RM05 User Guide.
1.4
SUBSYSTEM PEATURES AND CAPABILITIES
The RM05 performs error detection and error isolation operations
on all data as well as header information read from the disks.
These error detection and correction operations permit the
software to correct detected errors and recover data that would
normally be lost.
The drive can also accept offset commands that cause the heads to
move a fixed 250 micro inches to ei ther side of track centerl ine.
These program-controlled offsets allow the recovery of data that
is not normally read'due to head misalignments.
Da ta is recorded on the disk in fixed-number sector blocks,
32
sectors for a 16-bit format.
These sector blocks have headers
which contain the unique cylinder, sector, and track address.
They also provide for manufacturer or user-specified codes to
indicate that the ~ector is unacceptable for data storage.
The RM05 incorporates an integrated backplane that permits dualported, matched-impedance MASSBUS connections to be made directly
to the backplane.
This feature eliminates the requirement for
multiple internal cables for the interface.
The integrated
backplane also simplifies the interconnections of MASSBUS cables,
and allows up to e ig h t RM" 5 s to bed a i s y - c h a i ned fro m a
controller.
The dual-port capability of the RMa5 allows it to be
accessed by two different RH controllers.

1-6

STORAGE
CANISTER

B01TOM
DUST

COVER

CZ·CU37

Figure 1-2

RM0SP Disk Pack

Extensive diagnostic programs are available for maintenance
procedures. An o:ff-line tester, used to isolate drive-associated
faults, 1s also available.
The diagnostics and tests are
discussed in Chapter 2 and in Appendix A.

1-7

Table 1-1

RM85P Pack Data Capacity

Data Word Format

18-Bit Format

16-Bit Format

Sectors/data track
Data bytes/sector
Data bytes/surface
Data bytes/pack
Data bits/surface
Data bits/pack

38
512
12,614,280
240,184,320
111,130,240
1,921,474,568

32
512
13,484,032
256,196,608
109,472,256
2,049,572,864

NOTE
Data capacity is the customer-usable
data area.
1.5
REFERENCE DOCUMENTATION
Hardware documentation related to the RM05 is listed in Table 1-2.
Table 1-2

Reference Documentation

Name

Microfiche
Number

Hard Copy
Number

RM05 Disk Drive User Guide

N/A

EK-ORM05-UG

RM05 Disk Drive Service Manual

EP-ORM05-SV

EK-ORM05-SV

RM05 Disk Drive Maintenance
Print Set

N/A

MP-01075

EP-ORM05-IP

EP-0016A-IP

BK7B1E/F Disk Drive Illustrated
Parts Breakdown

N/A

ER-BK7BI-IP

BK7B1E/F Disk Drive Technical
Description

EP-BK7B1-TD

ER-B K7B I-TO

RM MASSBUS Adapter Technical
Description

EP-RMAOA-TO

EK-RMADA-TO

RM05 Disk Drive Illustrated Parts
Breakdown

1.6
SUBSYSTEM CONPIGURATION
The RM05 disk subsystem has two hardware element-s housed in two
cabinets.
One of the cabinets houses the disk drive, and the
second cabinet houses the RM adapter.

1-8

To operate this disk system, a high-speed MASSBUS controller is
needed to interface to the computer memory.
The controller
provides a high-speed path for ~~irect memory transfers.
Each
MASSBUS controller can handle from one to eight RM05 disk
subsystems as shown in Figure 1-3.

CENTRAL
""OCUIOR

r -'-----DISI( SUBSYSTEM UNIT 0

I
MASIIUS
CONTROLLER

----,

MAllaUI

IN
A

MAlsaus

Ol"

•
•

I
I
I

MAII.US
ADA'TER

INTERNAL

DISK
DRIVE

OUT

I
I
I
I
I
I

L----- T - - ----'
U'TO EIGHT UNITI TOTAL
IN DAIIV CHAIN CONNECTION

r -----..!...------,
DISlt SUBSYSTEM UNIT 7

INIERT
TERMINATOR
DEC 'ART NO.
7012283·00
ON LAIT DRIVE

I
I

lIN
T

OUT

MAllaus
ADAfllTER

I
I

•
I
I
I
I
•
IL __________ --'I
IN

OUT

Figure 1-3

DISK
DRIVE

Single-Port Subsystem Configuration
1-9

The RM05 uses the. RH780 Controller to interface with the
VAX-11/7S9, and the RH70 controller to interface wi th the PDP
11/79.
The RM05 disk subsystem also has a dual-port capability that
allows each drive to be controlled in a time-shared fashion from
two separate MASSBUS controllers.
Figure 1-4 shows how this
dual-port option is configured.
LAST DRIVE
TERMINATORS

PORT
B

PORT

A
DISK
SUBSYSTEM

r---'"I
I CENTRAL

PROCESSOR

I #1

OUT

r---'

UP TO EIGHT
DISK SUBSYSTEMS
CAN BE DAISY
CHAINED

I CENTRAL I
PROCESSOR I
I #2
I
L_
_.J

•

_.J
MASSBUS A

IN
RH
MASSBUS
CONTROLLER
A

OUT

PORT

B
DISK
SUBSYSTEM

RH
MASSBUS
CONTROLLER
B

MA·0847

Figure 1-4

Dual-Port Subsystem Configuration

1-19

1.7
DUAL-PORT CONPIGURATION RESTRICTIONS
The RM05 Disk Drive can be accessed for dual-port operation using
four RH MASSBUS controllers.
This configuration would have 8
total of eight MASSBUS cables entering and leaving the RM adapter
cabinet.
However, due to restr icted apace wi thin the AM adapter
cabinet, it is not possible to have eight MASSBUS cables mounted
in the cabinet. Therefore, the only configuration possible is to
have the RM05 Disk Drive accessed for dual-port operation using
only two RH controllers. Thi~ configuration, shown in Figure 1-4,
requires only four MASSBUS cables in the RM adapter cabinet.
1.8
SUBSYSTEM SPECIPICATIONS
Performance, power, environmental, and physical specifications for
the RM05 Disk Subsystem are listed in Table 1-3. The specifications for the disk pack are provided in Table 1-4.

Table 1-3

RM05 Specifications

Specification

Limit

Seek time
Maximum seek (822 cylinder)
One cylinder seek (maximum)
Average seek
Seek to the same cylinder

S5 milliseconds
6 milliseconds
30 milliseconds
4 microseconds

Latency
Speed
Maximum latency
Average latency

3600 revolutions/minute
17.3 milliseconds
8.33 milliseconds

Start/stop time
Start (maximum)
Start (typical)
Stop with power (maximum)
Stop with power (typical)
Stop wi thout po'wer

35 seconds
25 seconds
3S seconds
25 seconds
120 seconds

Heads
Servo head
Read/write heads

Data rates
Bit cell time
Word rate

103.3 nanoseconds
1.65 microseconds

1-11

Table 1-3

RM85 Specifications (Cont)

Spec{fication

Limit

Number of addressable registers
in RM05 adapter

Error detection/correction

3 2 - bit Err 0 reo r r e c t ion
(ECC)/sector

Time for correction

4.47 milliseconds (maximum)

Co d e

Temperature

Operating:

15.0 0 to 32.2 0 C (59 0 to 90 0
with
maximum gradient of 6.7
C (12 F) per hour.

Non-operating:

-40 0 to 70.0 0 C (-40 0 to 158 0 F)
witb a maximum gradient of 2,,0 C
(36 F) per hour.

Relative humidity
Operating

29 to 89 percent (providing
there is no condensation)

Non-operating

5 to 95 percent (providing there
is no condensation)

Altitude
Operating

305 meters (1000 feet) below sea
level to 2009 meters (6500 feet)
above sea level

Non-o pera t ing

395 meters (1000 feet) below sea
level to 4572 meters (l5,et00
feet) above sea level

Electrical
Voltages available
(Drive)

208
239
220
249

Voltages available
(RM adapter)

120 (+8.0, -8.0) , 60 Hz
220 (+15.0, -25.0) , 50 Hz
240 (+17.0, -27.0), 50 Hz

1-12

(+14.6, -29.0), 60 Hz
(+14.5, -32.0) , 6A Hz
(+15.0, -25.0) , 50 B?!
(+17.0,' -27.9), 50 Hz

'reb1e 1-3

AMI5 Specifications (Cont)

Specification
Start current

Limit
208 Vae,
maximum
230 Vae,
maximum
220 Vae,
maximum
240 Vae,
maximum

60 Hz

39.0 A

rms,

40.0

rms,

50 Hz

40.0

A rms,

41.0

rms,

Line current
Disk and carriage in motion

208 Vac,
230 Vac,
220 Vac,
240 Vac,

60 Hz @ 8.0 A rms, max.
60 Hz @ 7.2 A rms, max.
50 Hz @ 9.5 A rms, max.
50 Hz @ 8.7 A rms, max.

Disk not in motion

208 Vac,
230 Vac,
220 Vac,
240 Vac,
120 Vac,
220 Vac,
240 Vac,

60 Hz @ 2.0 A rms, max.
60 Hz @ 1.8 A rms, max.
50 Hz @ 2.5 A rms, max.
50 Hz"@ 2.3 A rms, max.
60 Hz t' 2.1 A rms, max.
50 Hz @ 1.3 A rms, max.
50 Hz @ 1.4 A rms, max.

R.M

adapter

Line cord length

Disk ca~tridge type

366 centimeters (12 ft) 14 wire
gauge already installed
fo r
NON-VDE RM05
366 centimeters ( 12 ft) 14 wire
gauge pluggable for VDE RM05
RM05P

Weight
RM05 drive with cabinet

550 Ibs

adapter cabinet
W/l adapter
W/2 adapters

:120 lbs
200 lbs
:280 lbs

R.M

AC plug type

RM05 drive
120 volts, 60 Hz
208 volts, 50 Hz

NEMA L6-20P

RM adapter
120 volts, 60 Hz
240 volts, 50 Hz

NEMA 5-15P
NEMA 6-15P
1-13

Table 1-4

RM8SP Disk Pack Specifications

Specification
Type

Limits

RM05-P

Disk diameter

35.56 cm (14 inches)

Number of disks

12 (the upper and lower disks are

Number of recording surfaces

19 read/wr i te
servo surface

Cylinders per disk pack

823

Total number of tracks

15,637 per disk pack

Tracks per cylinder

Tracks per inch

384

Bad sector file

Cylinder 822, track 18

not used for recording)
and one read-onl y

Temperature range
Operating

to 57° C (50 0 to 106 0 F);
temperaturs chang~ rate not to
exceed 0.1 C (0.2 F) per minute

Non-operating

to 65 0 C (-40 0 to 150 0 F);
temperatuoe cha~ge rate not to
exceed 14 C (25. F) per hour

10 0

-40 0

Relative humidity
Operating and
no n - 0 pe rat i ng

8 to 80 percent

Wet bulb reading
0

Operating

25° C (78

F) maximum

Non-operating

30 0 C (85°.F) maximum

Altitude
Operating

Sea level to 3, 050 meter (10,000
ft)

Non-operating

Sea level to 12,190 meter (40,000
ft)
1-14

Table 1-4

AMe5P Disk Pack Specifications (Cont)

Specification

Limits

Stray magnetic fields
Operating and non-operating

Not to exceed 50 oersteds

1.9
NON-VDE/VDE RMIS SUB-ASSE.'BLIES
The major sub-assemblies of the NON-VDE RM0S are shown in Figure
1-1 and are described In Table 1·-5. The major sub-assemblies of
the VDE RM0S are shown in Figure l-IA and are described in Table
I-SA.
The BK7BIE/F Illustrated Parts Breakdown and the RM35
Illustrated Parts Breakdown contain a complete list of RM0S parts.
Chapter 4 of this service manual explains how to remove, replace,
and repair the major subassemblies of the RMes.

Table 1-S

NON-VDE RM0S Subassemblies

Sub-assembly

Description

Actuator

This contains the voice coil and carriage.
This assembly posi tions the heads over the
disk surfaces.

Blower assembly

This contains a blower motor that circulates
cooling air for the drive.

Deck cover

This provides an electrical interference
shield for the drive and reduces the noise
level output from the drive.

Drive motor

This provides rotational motion
the spindle and the disk pack.

Front door

This provides access to the blower assembl y
and the lower front part of the cabinet.

Heads

There are 20 heads, 19 of whi ch wr i te and
read data to and from the disk pack, and one
read only head which reads the servo data
from the dedicated servo platter.

Logic chassis

This contains logic cards that control
operation of the drive.

Magnet

This provides a permanent magnetic field that
is used in conj unct ion wi th vo ice co i 1 to
move the carriage and the heads.
I-1S

that

turns

the

Table 1-5

NON-VDE Drive Assemblies (Cont)

Subassembly

Description

Operator panel

This contains switches that allow the
operator to control and moni tor the basic
drive operation.

Pack access cover

This provides
pack area.

Pack access cover
solenoid

This prevents the pack access cover from
being opened while the pack is spinning.

Pack access cover
switch

This interlock de-energizes the drive motor
if the pack access cover is opened while the
pack is spinning.
An open cover also
prevents the motor from starting.

Pack on switch

This interlock prevents the drive motor from
starting when the pack is not installed.

Parking brake

This keeps the spindle from spinning while
the disk pack is being installed or removed.

Powe r suppl y

This furnishes all necessary voltages for the
drive operation.

Read/write chassis

This contains the modules
read/write operations.

Rear door

This provides access to the power supply,
logic chassis, and lower rear of cabinet.

Shroud and
sh roud cover

This provides protection and ventilation for
the pack.

Side panels

This provides access to either side of
drive.

Spindle and
lockshaft

This provides a mounting surface for the disk
pack. The lockshaft secures the disk pack to
the spi ndle.
The dri ve motor transm i ts a
rotational motion to the spindle via the
drive belt, causing pack rotation.

Top cover

This covers the entire top of the drive,
protecting drive assemblies and reducing
noise level.

1-16

access

the

disk

used

pack and

drive

the

~8ble

l-SA

VDE AM,S Subassemblies

Sub-assembly

Description

Actuator

This contains the 'voice coil and carriage.
The assembly posi tions the heads over the
disk surfaces.

Blower assembly

This contains a blower motor that circulates
cooling air for the drive.

Deck cover

This provides an electrical interference
shield for the drive and reduces the noise
level output from the drive.

Drive motor/brake

This provides a rotational motion that turns
the spindle and the disk pack as well as a
(dynamic)
brake used to stop spindle
rotation.

Front door

This provide!; access to the blower assembly
and the lower front part of the cabinet.

Heads

There are. 20 heads,' .. 19 of· which. wr i te and
re~d data to and from·the disk pack, and one
read only head which reads the servo data
from the dedicated servo platter.

Logic chassis

Thi s conta ins the log ic cards that control
the operation of the drive.

Magnet

This provides a permanent magnetic field that
is used in conjunction with the voice coil to
move the carriage and the heads.

Operator panel

This contains switches that allow the
operator to control and mon ito r the basic
drive operation.

Pack access cover

This provides access to the disk pack and
pack area.
The pack access cover cannot be
opened for approximately 30 seconds after
main AC power has been applied.

Interlock Assembly

This interlock combines the pack access cover
solenoid and the pack access cover swi tch.
It prevents the pack access cover from being
opened while the pack is spinning. The pack
access cover can now only be opened when the
pack is stopped and the ma in AC power is
applied.

1-17

Table 1-5

NON-VOl Drive Assemblies (Cont)

Subassembly

Description

Parking brake

This keeps the spindle from spinning while
the disk pack is being installed or removed.

Power supply

This furnishes all necessary voltages for the
drive operation.

Read/write chassis

Th i s con t a ins the mo d u 1 e sus e din d r i v e
read/write operations.

Rear door

This provides access to the power supply,
logic chassis, and lower rear of cabinet.

Shroud and
shroud cover

This provides protection and ventilation for
the pack.

Side panels

This provides access to either side of the
drive.

Spindle and
lockshaft

This provides a mounting surface for disk
the pack.
The lockshaft secures the disk
pack to the spindle.
The drive motor
transmits a rotational motion to the spindle
via the drive belt, causing pack rotation.

Top cover

This covers the entire top of the dr ive,
protecting drive assemblies and reducing
noise level.

1.19

RM ADAPTER SUB-ASSEMBLIES

Refer to the

RM MASSBUS AdB1ter
EK-RMADA-TD-~~l
for
locat on

sub-assemblies.

1-18

Technical Description manual
and description of
these

CHAPTER 2
!!!!ALLATION AND CHECKOUT PROCEDURES

2.1

INTRODUCTION

This chapter contains information concerning the installation and
checkout of the RM05 Disk Drive. The person performing these procedures should be familiar with the operation of the drive and
wi th all informat :10n in the general ma intenance area of the RM05
Service Manual.
WARNING
Hazardous voltages are present inside
this equipment.
Installation and
'servicing should be' perfor.ed . only by
qualified
and
trained
service
rapresentatives.
Bodily injury or
equipment damage may result
from
'improper serviclng~
Refer to the
service manual for proper instructions.

This chapter is divided into the areas listed below.
o
o
o
o

Site preparation and planning
Unpacking the drive
Drive installation procedures
Initial checkout and start-up

2.2
SITE PREPARATION AND PLANNING
Site preparation and planning enabl'e a user to layout a site in
The most advantageous manner based upon space available and power
requirements. The location of the RM05 Disk Drive must present a
class A computer room environment, 'which includes controlled
temperatures, humidity, and filtered air flow.

The RM05 01 sk Dr ive may be located alone or in 1 ine wi th othe r
drives and adapters. Whichever method is used must provide sufficient clearances around the unit to permit access for maintenance.
These space requirements are shown in Figure 2-1.

2-1

15.2 CM
(6.0 IN)
....

914CM
(36.0IN)--

7',
)
/
/
/
I

I
~

152 eM

"- ~.

OINIT

92 eM
(36.2 IN)

""" L 50.8 CM J

L 50.8CM J "'"

r- (20.0 IN)""

~
-,--

58'4CMt-

(23.0 IN)
57.1 eM

54.6 CM

(22.SINI--l

(21.SINI--j

20.3 CM
(SIN)

([Q]

--*--

(20.0 IN)""

([gJ

U
CZ-G121

Figure 2-1

Space Requirements

2-2

An ac power soure'e is required for each RM05 and adapter.
Both
drives and adapters connect to the power source via 3.6 m (12 ft)
power cords. The 60 Hz uni ts are shipped wi th a power connector
at tached.
The 5B Hz NON-VDE un! ts are not supplied wi th powe r
connectors, and· they must be obtained locally. The 50 Hz NON-VDE
connector should be wired as indicated below.
o
o
o

Green or green/yellow wire to ground
Brown wire to phase 1
Blue wire to neutral or phase 2
NOTE
A 6m Hz NON-YDE drive cannot be
converted to 51 Hz, or vice-versa,
without
.aking
hardware
changes
(transformers, spindle motor, modules
etc. )

The S0 Hz VDE units are shipped wittl a plugable power cord but not
shipped wi th a 50 Hz power connector.
The connector should be
wired as indicated below:
o Green or green/yellow to ground
o Black wire to phase 1
o' Black wire to neutral or'phase 2
NOTE
A 50 Hz Yde drive can be converted to a
68 Hz,' or vice verSII.
The' conversion
procedure is found In paragraph 2.3.2.1.
Table 2-1 lists the drive
consumption requirements.
Table 2-1
Input
Vol tage
V,
V,
V,
V,

60
60
S0
50

208 V,
230 V,
220 V,
240 V,

60
60
S0
50

208
230
220
240

Hz
Hz
Hz
Hz

input

voltage

tolerances

and

power

Drive Power Consumption Requirements

Unit
Status

Line *
Current

Consumption *
Kw
BTU/hr

Power
Factor

Disks and
carriage
in motion

8.£1 A
7.2 A
9.5 A
8.7 A

1.20
1.20
1.30
1.30

42£10
4200
4200
4200

.70
.70
.70
.70

Disks not
in motion

2.0 A
1.8 A
2.5 A
2.3 A

0.40
0.40
0.50
0.50

1400
1400
17S0
1750

.90
.90
.90
.90

Hz
Hz

*These are maximum values.
2-3

In addition to the requirements of space, environmental conditions
and power supply, each drive and adapter must be correctly
grounded to ensure safe and satisfactory operation.
Each drive
and adapter must have two ground connections, the site ac power
system ground and a system ground.
The site ac power system ground is provided by the green (or green
with yellow stripes) wire in the ac power cord.
This wire
connects to the dr ive frame and goes through the ac power cord to
earth ground via the ac branch circuit supplying the drive. Also,
all power receptacles in the vicinity of the drive must be at the
same ground potential as the drive.
The power system safety ground does not necessarily satisfy all
system ground ing requl remen ts.
Therefore, add i tional connec tions
to earth ground are required to ensure proper drive and system
operation. This Is referred to as the system ground.
The system
ground can connect to earth using any of the methods given below.
o

Floor Gr id (grounded) - The drives and controller are
connec ted to a floor gr id consi st Ing of hor i zon tal and
vertical members which are mechanically secured and have
ground straps joining them.
The ground straps ensure a
constant ground potential at all points on the grid.
This grid is located under a false floor and connects
drirectly to earth ground.

Floor Grid (not grounded) - The drives and controller are
connected· to a floor grid that is isolated from earth
ground.
In this case, the controller is connected
directly to earth ground, which grounds the entire grid.

Daisy-Chain
The ground terminals on the drive are
connected in a daisy-chain to one another 'and then to the
controller which connects to earth ground.
NOTE
The daisy-chain method of grounding the
system is not recommended in systems
containing more than ten drives.

2.3
UNPACKING THE DRIVE
Both drive and adapter cabinets must be properly packed whenever
they are shipped from one location to another.
Use the procedures
given below to unpack the units of the drive. Pr ior to unpacking
the units, examine the cartons for any damage caused during
shipment.
2.3.1
Unpacking the Drive Cabinet
Use the procedure below to unpack the drive cabinet.
1.

Pry away four external 1 x 4s from the carton.

2-4

Lift off the corrugated cover from carton.

Remove the unload ing ramp' from top of carton.

Remove the strapping and wood framing by carefully prying
the upr ight wood corners slightly away from the uni t and
lifting the carton off.

Remove the polyethylene dust cover from the drive.

Open the unit rear door and remove manuals, leveling
legs, filter, and power cable. Logical address plugs are
packed with the manuals. Close the rear door.

Install the ramp on the pallet (see Figure 2-2).

Sa.

If a l i ft truck or hoist 1s to be used, li ft the cabinet
clear of the pallet at this time.
Remove the pallet and
install the level ing legs before lower ing the uni t to
the floor. Then proceed to step 10.

Sb.

If no lift track or hoist is available, then proceed to
step 9.

Roll the drive cabinet down the ramp to the floor.
CIENTER ON END OF PALLET
START LAG SCREW BY
HAMMERING INTO SKID
THEN USE WRENCH

Figure 2-2

Installing Ramp on Pallet

2-5

NOTE
Use the procedure given below to install
leveling legs on the RM8S drive and the
RM adapter cabinet.
o

If the site has a raised floor,
remove a panel from the raised floor
and install leveling legs on the
front of the cabinet.
Replace the
panel and repeat the procedure for
the rear of the cabinet.

If the 8i te does not have a raised
floor, raise the cabinet off the
floor and ·place a block of wood
under the cabinet.
Install legs_
Remove the block of wood and repeat
the procedure for the rear of the
cabinet.

10.

Insert the filter in the filter bracket under the front
base frame.
(See Figure 2-3.)

11.

Open the front and rear doors, raise the top cover to the
open latched position, and remove the actuator shield and
the side panels. The rear door on VDE un i ts have an
add i t 10nal la tch.
Use a 6mm Allen wrench to open thi s
additional latch.
NOTE
To perform Steps 12 through 28 for
unpacking the RM8S, refer to Figure 2-3
for NON-VDE units_ Refer to Figure 2-3A
for VDE units.

12.

Remove the front deck hold-down screws between the upper
frame and deck casting_
(On units with a safety shield
installed, remove the shield to remove items in steps 12
and 13.)

13.

On NON-VDE UNITS, remove the two wood blocks adjacent to
the screws between the deck casting and unit frame.

14.

On VDE units, there are no wood blocks to remove.

15.

Remove the foam block between the blower assembly and the
deck casting_

16.

Remove the two shipping screws in the motor plate.

2-6

ACTUATOR ftI~ HERE
DURI~G OPERATION

REMOVE PLYWOOD

INSEFIT FIL TH~
-'1)( l ' X ,

.-oWER
.,."";i.4---SUPPL Y

NO~·METALL'C
STRAPftl~G

Figure 2-3

Cl GloW

Unpacking NON-YDE RM95 Drive

2-7

ACTUATOR PtN HERE
DURING OPERA110N

REMOVE PlYWOOO
INSERT FILTER
'/JX17X7

FOAM BLOCK

MOTOR RELAY BOX

NON· METAlLIC
STRAPPING

cz. .

Figure 2-3A Unpacking RM05 VDE

17.

Close the front door.

18.

Remove the logic chassis latch tape.

19.

Remove the plastic caps at the rear of the deck surface.
Remove the rear deck hold-down screws below these caps,
and then replace the caps.

20.

Remove the shipping pin on the top of
Place pin in the adjacent storage hole.

21.

Remove the strap and block from around and between the
power supply and the blower assembly.

22.

Attach the power cable.

the

Refer to Figure 2-3.

2-8

actuator.

23.

any remaining packing materials, then replace and
close all covers and doors.

Rem~ve

2.3.2
Unpacking RM Adapter Cabinet
Use the f~llowing procedure to unpack the AM adapter cabinet.
Rem~ve

Remove plastic corners.

Remove top cover.

Remove

Rem~ve

Remove the polyethylene bag from the cabinet.

Remove the plastic strapping which attaches the cabinet
to the pallet.

Remove the plastic corners which were under the plastic
strapping.

Remove two 1/2 inch, 1:3 x 3 1/2 hex-head bol ts wh i ch
attach up through the corners of the pallet into holes in
the floor of cabinet.

10.

Remove the cabinet from the pallet.
(The ramp provided
wi th the d rive cabinet may be used to roll the cabinet
from pallet to floor.)

11.

tw~

pl.stic straps which hold container together.

f~ur

corrugated cardboard corner posts.

the cardboard sleeve from around the cabinet by
lifting it over the top of the cabinet.

•
Lift the front of the cabinet
sever,al inches off the
floor.
Thread the leveling legs into the h~les in
corners of the cabinet.

12.

Lower the front of the cabinet to floor.

13.

Lift the rear of the cabinet several inches off
floor.
Thread the leveling legs into holes in
corners of the cabinet.

14.

Lower the front of the cabinet to the floor.

15.

Rem~ve

the
the

any remaining packing residue.

2.3.3
Unpacking RM Adapter
Use the following procedure to unpack the RM adapters not shipped
in an RM adapter cabinet.
1.

Remove the straps that secure the carton to the pallet.

2-9

Remove the plastic corners and tape used to close the top
of carton.

Remove the
carton.

Remove the die-cut top from the inner carton.

Remove the adapter from the inner carton.

Unwrap the bubble wrap from the adapter.

Remove any remaining packing residue.

Set the
cabinet.

polyester

adapter

foam

the

piece

upper

froln

rails

the

top

the

adapter

2.4
DRIVE INSTALLATION PROCEDURES
This paragraph describes the installation of the drive.
These
procedures assume that the requirements discussed under site
preparation have been met.
'
All the procedures listed below should be considered in the order
presented. However, this order may have to be varied somewhat to
meet requirements of specific installations.
o

o
o
o
o
o

Preinstallation inspection
Grounding
AC power wi ring
Power cable routing
I/O cable installation
Logical address plug installation
Cabinet leveling

•

2.4.1
Preinstallation Inspection
Perform the following inspection prior to installing the RM0S Disk
Drive.
1.

Inspect the drive for possible shipping damage.
Any
claim for this type of damage should be filed promptly
with the transporter involved. If a claim is filed, save
the original shipping materials.

Verify that all logic cards are firmly seated in logic
chassis.

Verify that all connectors are firmly seated, and tighten
any loose hardware.

Verify that the control panel is firmly seated in front
bezel.

2-111

Verify that all cabling is intact and that there are no
broken or damaged wires.

Check entire drive for presence of foreign material which
could cause an electrical short.

Check actuator. and pack area for presence of mater ial
which could obstruct movement of carriage and heads.

2.4.2
Daisy-Chain Grounding - If a floor grid is not available, (refer to Figure 2-4) all drives must be connected to the
controller in a daisy-chain grounding configuration (refer to
Figure 2-5).
The CPU cabinet must then be connected to earth
ground. When connected in this configuration, the drive must have
a common ac and de ground. Therefore, the jumper on the grounding
block must be connected (refer to Figure 2-5). This procedure is
descr i bed below.

CONTROLLER
DRIVE

-DC AC

DC AC

,,•

2 ,~

I
I
/
1 ...L

-EARTH /
GROUNDS

Figure 2-4

DRIVE

DC AC

, •

':" ,

DRIVE

2'I

DC AC
t

2'I

1 NOTES
":'

1 REOUIRED ONLY IF FLOOR
GRID IS NOT GROUNDED
2 REQUIRED ONLY IF DRIVE
HAS ISOLATED AC AND DC GROUNDS

Grounding to Floor Grid

Cut lengths of number four black grounding wire required
to go from drive to drive, the first drive in the chain
to the CPU cabinet. and from the CPU cabinet to earth
ground.

Crimp and solder terminal lugs to ends of each strap.

Connect the straps to the terminal of the grounding
block, route straps through I/O cable guide and connect
to each of the drives.

Connect the braided ground wire shipped with each drive
between the drives and RM adapter cabinet.
2-11

BRAIDED GROUNDWIRE
SHIPPED WITH EACH DRIVE

RH
CONTROLLER

DRIVE

CPU
CABINET

EARTH
GROUND

Figure 2-5
5,.

2.4.3

NUMBER 4 BLACK GROUND
WIRE, 25 FT. IN LENGTH

CZ·0124

Daisy-Chain Groundng Connection

Ensure that the following conditions exist.
o

All drives
chain.

and

Adapter

are

connected

daisy-

The drive closest to the CPU cabinet is connected to
the CPU cabinet.

The CPU cabinet is connected to earth ground.

AC Power Wiring

The NON-VDE drive comes from the factory wired for 208 volts, 60
Hz input power.
It is possible to rewire the drive for 230 volts,
6et Hz by moving wires on transformers AITl, AIT2~ and A1T3.
The
required transformer wiring for each input voltage is shown on
Figure 2-6.
Note that a 60 Hz NON-VDE drive cannot be converted
to 50 Hz without making additional changes (see paragraph 2.1).
2.4.3.1 VDE 50Hz To 60Hz Conversion
VOE units have the
capability of being converted from 50 Hz to 60 Hz, or 60 Hz to 50
Hz.
In some cases, converting from one power frequency to another
requires that a~ operating voltage conversion be made.
If only an
operating voltage change is required (frequency remains the same),
refer to Figure 2-6A for selection of the appropriate voltage
taps.
The following procedure details the steps required to
convert a VOE unit from 50 Hz to 60 Hz, or 60 Hz to 50 Hz
operation.
WARNING
Disconnect all
input power before
perfor.ing any power conversions.

2-12

TRANSFORMER
TERMINAL STRIP

r----

230V/60HZ
24OV/50HZ. 208V/60HZ

220V/SOHZ

-01
::2
:3

A1T1

:4
:5

_
23OV~OHZ
-0 1
24OV/50HZ;208VioHz
-2
·220V/50HZ

A1T2

-4

~ 1

- -__~~!"!!"!"'!.~+-<l: 2

A1T3

240V/50HZ :!,!!V!>~ _ -0 3
230V/60HZ
220VISOHZ

Figure 2-6

NON-VDE Transformer
Input Voltages

2-13

RETURN --(..;,...-.....

200V

50 OR 60HZ --o~-111(

208V

220V

230V

240V

,..._ _ _ _T_2_ _ _ _ _ _ _ _ _ _~ TO BLOWER MOTOR

60HZ
RETURN

200/208V

60HZ

230V
200V

220V
240V

50HZ

J1
60HZ

NOTE:
1 CONNECT BLOWER MOTOR
CONNECTION TO T2 CONNECTIONS
50 HZ TAP 4
AS FOLLOWS:
60HZ TAP 2
NOTE:
2. FOR 50HZ. MOVE P2 AND
CONNECT TO J 1 FOR 60 HZ.
LEAVE P2 CONNECTED TO J2.
NOTE:
3. CONNECT HOT LEAD OF C 1
TO EITHER 50HZ OR 60HZ
DEPENDING ON WHICH FREQUENCY
IS DESIGNEO.
CZ·0I37

Figure 2-6A VOE Transformer Input Voltages
2-14

2.4.3.2 Required Parts - The following parts are required to
change the drive so it will operate on a different line frequency.
Cnnversion from 60 Hz to 50 Hz requires that the listed parts be
50 Hz. Conversion from 50 Hz to 69 Hz requires 60 Hz parts.
PARTS

DEC PART
Hz I 50

DEC PART

Drive motor and
pully assembly

29-2:3896

29-23895

Drive belt

29-23584

29-23575

Ho ur meter

29-23898

29-23909

Power cord

Hz • 60

NOTE
Remove' power connector supplied wi th
power cord and replace wi th a power
connector suitable for local power
receptacles.
2.4.3.3 Conversion Procedure
1.

Power down the drive.

Open the rear door, raise the top cover, and remove the
right side panel.

Disconnect the power cord at the power source and at the
Connector on the power supply control p~nel.

Remove the power supply top cover.

Refer to Figure 2-6A and determine the input tap on
transformer T1 that matches the required operating
voltage and frequency.
Reposition the T1 input (hot)
lead to the appropriate tap.

Discharge the tuning capactor (C1) on transformer T2.

Reposition the tuning caspacitor
appropriate 58 Hz or 60 Hz terminal.

Reposition plug P2 on the appropriate transformer T2
output cable jack. P2 must connect to J1 for 60 Hz, or
J2 for 50 Hz operation.

2-15

(+)

lead

the

9..

Refer to logic diagram cross reference number 804 and
determine the input tap on transformer T2 that matches
the requi red operating vol tage.
Reposi tion the input
lead (hot) to the appropriate tap.

10.

Remove the hour meter and replace it with the appropriate
50 Hz or 60 Hz unit.

11.

Carefully check the power supply for properly
cables, loose connections, and lead dress.

12.

Install the power supply cover.

13.

Remove the drive motor and brake assembly
procedure in Chapter 4 of this manual.

14.

Obtain and drive motor and pulley assembly, and a drive
belt with the required voltage and frequency ratings.

15.

Remove the hysteresis brake from the existing motor.
Assemble it on the new motor using the procedure in
Chapter 4 of this manual.

16.

Install the motor and brake assembly, and drive belt,
into the drive using the procedure in Chapter 4 of this
manual.

17.

Obtain the required
install it.

and

18.

Connect the power cord.

19.

Power up the drive and check all vol tages at
points on the power supply control panel."

the

test

2~.

Close the top cover and rear door.

(60

the

Hz)

Drive Power Cable Routing

The drive power cable is routed
( ref e r to Fig ur e 2 -7 and 2 - 7 A) •
1.

cord

using

2.4.4

power

routed

and

connected

Remove screws secur ing cable guide
cable guide.

shown

below

frame and

remove

WARNING
Ensure MAIN AC c i rcui t breaker on the
wall is set to OFF when connecting power
cable.

2-16

1E~:--~~.f--_ _ CABLE SUPPORT SPRING

"...~~~~+---- POWER SUPPLY

CABLE GUIDE

Figure 2-7 NON-VDE Power Cable Routing

iiIIIo"""~~ . . . .1 M -_ _

POWER SUPPLY

AC POWER CABLE
~--'--=-CABLE GUIDE

Figure 2-7A VDE Power Cable Routing
2-17

Route power cable
power receptacle.

through

cable

guide

and

connect

Position cable guide on frame and secure with screws.

Connect support spring to power cable.

Connect power cable using cable clamp.
2-7A.

Refer to Fig ure

WARNING
Ensure ac power wiring procedure has
been properly performed before connecting power cord connector to site source.
6.

Connect power cord connector to site power source connection.

Turn all CS' s off except main CB.
Check power and turn
all other CS's on, checking voltages.

2.4.5

I/O Cable Installations

This procedure describes the installation of drive I/O cables.
1.

Remove power from drive by setting site MAIN AC circuit
breaker to OFF.

Remove left side panel. To remove side panel you must
first open rear door, then raise the top cover. This is
required because of the safety latches on the side
panel~ •

Remove screws securing I/O cable guide "(refer to Figure
2-9) and remove guide.
CAUTION
Use care not to damage cables between
I/O panel and logic chassis when performing the following steps.

Turn I/O panel fastener (refer to Figure 2-8) counterclockwise and remove I/O panel from upright support.
This will allow I/O panel to be positioned so cables can
be easily installed.

Remove hardware securing I/O panel cover to I/O panel and
remove cover.
NOTE
All cables installed in the following
steps are routed .through the I/O cable
cutoff (opening left by removal of cable
guide).
2-18

tCAILE FROM

I~OGIC CHASSIS

II.M-III---I/O CABLES

1 II, TURN FASTENER
REMOVES PANEL

P1 FROM
ADAPTER CABINET
(SHOWN PLUGGED
INTO IJ3)

P1 FROM
ADAPTER CABINET

fSHOWN PLUGGED
INTO IJ2)

NOTE
1. TO INSURE GOOD GROUND
CONNECTION ON 1/0 CABLES.
SCRAPE PAINT OFF ACCESS COVER.

CZ·0643

Figure 2-8

I/O Cable Routing

2-19

Connect cable 8 from adapter to drive I/O panel connector
IJ2.

Connect cable A from adapter to drive I/O panel connector
IJ3.

Replace I/O panel cover on I/O panel and secure.

Position I/O panel on upright support and secure.

1~.

Replace I/O cable guide ensuring the cables are routed as
shown in Figure 2-8.

11.

Replace left side panel.

2.4.6
Logical Address Plug Installation
The RM05 Disk Drive can have any logical address from 0 to 7. The
address of a particular unit is determined by the logical address
plug installed on the operator control panel.
Determine the
r10gical address of the drive in the system and install the proper
logical address plug.

NOTE
Only one unique number is allowed on the
Massbus
irregardless
of
the
port
selected.
2.4.7
RM Adapter Cabling
Use the procedure given below to install the ac power cable,
MASSBUS cables, cables A (69 position) and B (26 position), power
sequence cable, and frame grounding cables.
It is important to
follow the procedures outlined to allow enough slack in cables so
adapters can be pushed to front and rear ends of slides for
maintenance.
These procedures will also help ensure that cables
do not catch or bind as the adapters are moved for access.
Prepare the adapter cabinet for cable installation by performing
the tasks listed below.
Remove front door.
1.

Unlock the door

Remove the ground braid.

Pull down the upper hinge pin (spring-loaded).

Lift the door clear of the bottom hinge pin and set the
door aside.

2-21

Remove rear door.
1.

Unlock the door with Allen wrench (6 mm).

Remove the ground braid.

Lift the door to clear hinge pins from the hinge brackets
and set the door aside.

Remove shipping bracket.
1.

Remove six Phillips head screws holding the red shipping
bracket in place at rear of the RM adapter cabi-net.

Set the bracket aside.
(Save the bracket in case the
cabinet must be shipped at some future date.)

Replace and tighten the six Ph ill ips head screws in the
holes they came out of in the cabinet.

2.4.7.1 Adapter AC Power Cable Routing - Use the procedure given
below to route the ec power cable (see Figure 2-9).

Cut ties on power cable.

Fasten tlhe adhesive tie wrap mount to the side of the
plenum.
Place mount against the rear flange of plenum,
1-1/4 inches down from top.

Fasten the power cable to the tie wrap.

Push the
locks.

Remove tlhe cable access slot cover
the cabinet.

Put the power cable through the cable access slot in the
bottom of cabinet.

7..

Fasten the adhesive tie wrap mount to the floor of the
cabinet.
Place the mount 1/2 inch to the rear of the
cable aClcess slot in line with the adhesive tie wrap
mount on plenum.

"Adjust the power cable to provide some slack and tighten
the tie wrap.

adapter

full

forward

2-21

the

slides,

from

the

till

bot tom

•

•
POWER
SEaUENCE
OUT

DC POWER IN

TIE WRAP

/10 CABLES

AC POWER
CABLE

GROUNDING LUGS
CZ·OI1I

Figure 2-9

Cabling Single-Port Drive (Single Adapter)
2-22

2.4.7.2 MASSBUS and Power Sequence Cable Installation - Use the
procedure given below to route an~ install the port-A-in cable.

Br ing th~e adapter end of the cable in through the cable
access slot in the bottom of the cabinet.
Bring in at
the left side of the slot as viewed from the rear. Allow
about five feet of cable inside of the cabinet.

Fasten the adhesive tie wrap mount on the floor of
the cabinet directly' below the left rear corner of the
plenum.
Make sure the adapter 'is 'pushed fully forward
for proper positioning.

Tie the cable loosely with the
tightened later.

Make an eight inch clockwise service loop with the cable.
Start the loop by passing the MASSBUS cable under the ac
power cable.
Finish the loop by passing the MASSBUS
cable over the power cord.

Pass the connector end of the cable through the adapter
cable acc:ess on the left s ide of the adapter, as seen
from the rear.

Connect the cable
adapter backplane.

Remove the cable clamp from the the adapter card cage.

Place the
tighten.

Pull the excess MASSBUS cable back out of the cabinet,
maintaining an eight inch service loop with the adapter
fully forward.

lee

Tighten the tie wrap that was loosly fastened in step 3.

11.

If the adapter is the last one in a daisy-chain, install
the MASSBUS terminator on connector J2, and go to step
13. Otherwise, go to step 12.

12.

If this adapter is not the last in a daisy-chain, bring
the· power~ sequence cable and MASSBUS cable port-A-out
into the cabinet through the cable access slot.
Allow
about 5-1/2 feet of cable.
When viewed from the rear,
bring these cables in at the right rear of the cable
access s llot.

cable

port-A-in

the

2-23

clamp,

tie wrap.

connector

reinstall

will

clamp,

the

and

13.

Run cables over the top of the adapter power supply and
the connect the MASSBUS cable port-A-out to connector J2
and the power sequence cable to connector J9 of the
adapter backplane.

14.

Remove the cable clamp from the card cage.

15.

Place the cables
tighten down.

16.

Release the locks and push the adapter to the full rear
position.

17.

Rem~ve

the cable clamp from the power supply cover.

18.

Place

the cables on right-hand side of the regulator,
the clamp, and tighten down. (See Figure 2-9.)

the

clamp,

reinstall

clamp,

and

rein~ta11

19.

With the adapter fully to the rear, pull the exce~s cable
back through the cable access slot in bottom ~f the
cabinet.

2.4.7.3
Cable A (69 Position) Installation - Use the procedure
given below to properly install cable A from the drive cabinet to
the l~wer RM Adapter.
1.

Push the adapter fully to the front.

Remove the access
(Figure 2-10).

Remove M7687 and M7684 modules from the card cage.

Pass about 4-1/2 feet of cable A through the cable access
slot in bottom of the cabinet. Ground the cable to the
access cover using ground attached to cable.
See detail
on Figure 2-11 for proper grounding.

Route the cable forward, under the ac
through the MASSBUS service loop.

Bring the cable through A/B cable access hole along the
bottom side of the card cage to the front of the adapter.

Plug the cable connector
label facing up.

Guide the cable through the card guide and
into the adapter backplane slot A/F09.

cover

2-24

from

into

the

M7684

adapter

card

cage

power cable and

module,

with
plug

the

M7684

ACCESS
COVER

CARD LOCATOR CHART

~ FRONTO
3
4

•

-- -=-

--- -

-Mii23

M&922 M6e23-

_ _ _ _ _ _ _ _ _ _ _ M5922

6
6

~ TOP

<:J

,
2
3

M7886·YA

•

M768S·YA

M7187 - - -

M7684

8
9
CZ.o:"2

Figure 2-10

Adapter Card Cage

2-25

2.4.7.4
Cable B (26 Position) Installation - Use the procedure
given below to properly install cable B from the drive cabinet to
the l~wer RM Adapter.
1.

Pass about 4-1/2 feet of cable B through the cable access
slot In the bottom of the cabinet.
Ground the cable
to the access cover using the ground strap attached to
the cable.
See details in Figure 2-11 for proper
grounding.

Route cable B underneath cable A to
adapter.

Plug the cable connector into M7687 module with the label
facing up.

Guide the cable through the card guide and
into the adapter backplane slot EaS.

Place the cables in the cable clamp and secure it.

the

front

the

plug M7687

2.4.7.5
Frame Grounding Procedure
There are two frame
grounding studs on the floor of the adapter cabinet.
One is at
the left rear. The other is at the right rear (See Figure 2-11).
Bring the frame ground wires from the drives and CPU or floor
gr~unding grid into the appropriate side of the cable access slot
and fasten to the grounding stud on that side of the cabinet.
2.4.7~6
Final Securing of Adapter Cabinet - Use the procedure
given below to complete the cable installation and to prepare the
adapter for operation. See Figure 2-11 for details.

Push the adapter fully forward.

Remove all the clamps from the cable access slot cover.

Place the cover loosely over the access slot.

Route the ac power cable and MASSBUS port-A-out cable
over the cover and around the rear of the cover to exi t
the cabinet.

Route the MASSBUS port-A-in cable and cables A and
and 26 position) under the front of the cover.

Place cables A and B in the clamp and loosely install the
clamp on the underside of the access slot cover. Connect
the ground straps as shown in detail in Figure 2-11 to
the access cover.

Place the MASSBUS port-A-in cable in the clamp and
loosely install the clamp on the underside of the access
slot cover.
2-26

(6a

1/0 CABLE GROUNDS

A AND B CABLES
FROM IBOTTOM ADAPTER
ROUTE THROUGH 20CM (8 IN)
MASSBUS SERVICE LOOP

A AND B CABLES
:L_...-Ji~"1:- FROM UPPER ADAPTER

•

MASSBUS CABLES
FROM LOWER ADAPTER

MASSBUS CABLES
FROM UPPER ADAPTER

NOTE:
2. ALL CABLES SHOULD BE RUN AT THE SAME
TIME THIS PREVENTS ANY DISRUPTION DURING MAINTENANCE.
CLAMP CABLE BACK TO THE BOTTOM FRAME.

Figure.2-11

Cable Access Slot Cover

8..

Place the MASSBUS port-A-out cable and power sequence
cable in the clamp and loosely install the clamp on the
underside of the access slot cover.

Position the access slot cover over the mounting studs.

10.

Adjust the cables for the proper service loops.

11.

Tighten all the cable clamps.

12.

Secure the cable access slot cover.

2-27

13.

Tie wrap the cables as shown in Figure 2-9.

14.

Slide the adapter to
cables as required.

15.

Install and close the front and rear doorS.

the center

position,

guiding

the

2.4.8
Cabling Procedure for Second RM Adapter
Use the procedures given below for installation and cabling of the
second RM adapter in the adapter cabinet.
1.

Extend the top slides to forward position.

Set the adapter on slides.

Install the locking screws (see Figure 2-12).

LOCKING SCREWS

Figure 2-12

Adapter Rail Mounting
2-28

2.4.8.1
Adapter AC Power Cable Routing - Use the procedure given
below to route the ac power cable from the upper RM Adapter.
1.

Cut ties on the power cable.

Fasten the adhesive tie wrap mount to the side of
plenum. Place the mount In the center of the side of
plenum, flush ·with the top edge (see Figure 2-13).

Figure 2-13

Cabling Second Adapter in Cabinet (Single-port)
2-29

the
the

Plug the ac power cord into the ac power receptable (J4)
in the lower adapter.

Push the adapter full forward on slides.

Coil" the excess power cord and secure to tie wrap mount
just installed on the side of the plenum.

2.4.8.2
MASSBUS and Power Sequence Cable Installation - Use the
procedure given below to route and install the port-A-in cable to
the upper R~ Adapter.
1.

Pull the lower adapter to the forward position.

Remove the terminator from the connector J2 of the lower
adapter.

Connect the four foot MASSBUS port-A-in cable from
connector"J2 of the lower the adapter to connector J3 of
the upper adapter (see Figure 2-13).

Make a clockwise service loop in the MASSBUS port-A-in
cable, going from the lower to the upper adapter.

Secure the MASSBUS port-A-in cable to cable clamps on the
lower and upper adapter.

Connect the five foot power sequence cable from connector
J8 on the lower adapter to connector J9 on the upper
adapter.

Make. a clockwise service loop in the power sequence
cable, going from the lower to the upper adapter.

Route the power sequence cable as shown in Figure 2-13.

Install the MASSBUS terminator on connector J2 of the
upper adapter if this is the last adapter in a
daisy-chain.

10.

If it is not the last adapter in the daisy-chain, bring
the MASSBUS port-A-out cable in through the cable access
slot in the bottom of the cabinet.

11.

Run the cables over the top of the. adapter power supply
and connect the MASSBUS cable port-A-out to connector J2
and the power sequence cable to connector J9 of the
adapter backplane.

12.

Remove the cable clamp from the card cage.

13.

Place cables in the clamp, reinstall clamp, and tighten
down.
2-38

14.

Release the locks and push adapter to full rear position.

15.

Remove the cable clamp from power supply cover.

16.

Place the cables on right-hand side of the regulator,
reinstall clamp, and tighten down (see Figure 2-13).

17.

With the adapter f~lly to the rear, pull the excess cable
back through the cable access slot in the bot tom of the
cabinet.

2.4.8.3
Cable A (60 Position) Installation - Use the procedure
given below to properly install cable A frOom the drive cabinet to
the upper RM Adapter.
1.

Push the adapter fully to the front.

Remove the access
(Figure 2-14).

Remove M7687 and M7684 modules from the card cage.

Pass about 4-1/2 feet of cable A through the cable access
slot in the bOot tom ·of the cabinet.
It wi 11 go to the
rear of the cable access slOot cover. . Connect the ground
stray Oon the cable tOo the access cover. Refer to detail
in Figure 2-15.

Bring the cable forward thrOough the A/B cable access hole
along the bottOom side of the card cage to the front of
the adapter.

Plug the cable connector into M7684 module with the label
facing up.

cover

from

the

adapter

card

cage

Guide thE~ cable through the card guide and plug M7684
into the adapter backplane slot A/r09 •
•
2.4.8.4
Cable B (26 Position) Installation - Use the procedure
given below to prOoperly install the B cable from the drive cabinet
tOo the upper RM Adapter.
1.

Pass about 4-1/2 feet of cable B through the cable access
slot in 1the bottOom of the cabinet.
It will go to the
rear of the cable access slot cover. Connect the ground
strap on the cable tOo the access cover. Refer to detail
in Figure 2-15.

Route cable B beside cable A to the front of the adapter.

Plug the cable cOonnector into M7687 module with the label
facing up.

2-31

ACCESS
COVER

CARD LOCATOR CHART
A
1

2
3
4

FRONT¢

M5923

---------:.:.-----Ms922 M5i23-

2
3

- - - - - - - - - - - M5922

8 TOP
9

--- -- -- -- ----

5
6
7

M7686·YA
M7685·YA

M7687 - - M7684

5
6
7

8
9
CZ·OZ72

Figure 2-14

Adapter Card Cage (Upper Adapter)

2-32

1/0 CABLE GROUNDS

A AND B CABLES
fROM BonOM AOAPTER
ROUTE THROUGH 20CM (8 IN)
MASSBUS SERVICE LOOP

A AND B CABLES
2-~~,- fROM UPPER ADAPTER

MASSBUS CABLES
FROM LOWER ADAPTER

MASSBUS CABLES
fROM UPPER ADAPTER

NOTE:
2. ALL CABLES SHOULD BE RUN AT THE SAME
TIME. THIS PREVENTS ANY DISRUPTION DURING MAINTENANCE.
CLAMP CABLE BACK TO THE BOnOM FRAME.

Figure 2-15

Cable Access Slot Cover (Two Adapters)

Guide the cable throuqh the card quide and pluq M7687
into the adapter backplane slot E08.

Fasten the cable clamp on the bottom of the adapter about
two inches from the front edge of the card cage to secure
cables A and B.

Place the cables in the cable clamp and secure clamp.

2.4.8.5
Prame Grounding Procedure
There are two frame
ground ing studs on the floor of the adapter cabinet.
One is at
the left rear. The other is at the right rear (See Figure 2-15).
Bring the frame ground wires from the drives and CPU or floor
grounding grid into the appropriate side of the cable access slot
and fasten to the grounding stud on that side of the cabinet.
2.4.8.6
Pinal Securing of Adapter Cabinet - Use the procedure
given below to complete the cable installation and to prepare the
adapter for operation. See Figure 2-15 for details.
1.

Push the adapter fully forward.

Remove all the clamps from the cable access slot cover.

Place the cover loosely over the access slot.

Route the ac power cable and MASS8US port-A-out cable
over the cover and around the rear of the cover to exi t
the cabinet.

Route the MASSBUS port-A-in cable and
under the front of the cover.

Place the A and B cables in the clamp and loosely install
the clamp on the unders ide of the access slot cover.
Connect the ground connection (as detailed in Figure
2-15) to the access cover.

Place the MASSBUS port-A-in cable in the clamp and
loosely install the clamp on the underside of the access
slot cover.

Place the MASSBUS port-A-out cable and" power sequence
cable in the clamp and loosely install the clamp on
the underside of access slot cover.

Position the access slot cover over the mounting studs.

10.

Adjust the cables for proper service loops.

11.

Tighten all the cable clamps.

12.

Secure the cable access slot cover.

13.

Tie the wrap cables as shown on Figure 2-13.

14.

Slide the adapter to the center position, guiding cables
as requ ired •

15.

Install and close the front and rear doors.

2-34

cables A and

2.4.9
Dual-Port Option (Lower ~l Adapter)
Prepare the adapter cabinet for dual port installation as
below.

sh~wn

Cycle down the drive
the drive/adapter.

(If

necessary)

and

power

off

Rem~ve

the front door
switch cover plate

and

appropriate

the

dual

port

Unlock the door with an Allen wrench.

Remove the ground braid from the door.

Pull down the upper hinge pin (spring-loaded).

Lift the door clear of the bottom hinge pin and set
aside.

Remove the appropriate dual-port switch cover plate
from the front of the cabinet and set aside.

Remove the rear door.
a.

Unlock the door with an Allen' wrench.

Remove the ground braid from the door.

Lift ,the door to clear the hinge pins from the hinge
brackets and set the door aside.

Push the adapter to forward stop on slides.

Check the adapter backplane for a dual~port toggle switch
and two LEOs. If installed, proceed to the next step. If
not, g~ to step 7. (Refer to Figure 2-16 for location of
switch and LEOs).

Toggle switch and LED removal/replacement.
a.

Unsolder the two LEOs and the toggle switch from the
backplane using a low wattage soldering pencil.

Install one 3-pin female connector in the
where the toggle switch was located.

Install the two 2-pin connectors in the positions
where the LEOs were located. The connector labeled
-AM should be installed on the left side of the
female connector and the connector labeled -B" on the
right side.

2-35

positi~n

S1 (ACCEPTS P10)

PORT 8 LAMP POSITION
(ACCEPTS P12) - TWO WIRE
WRAP POSTS IN BACKPLANE

PORT A LAMP POSITION
(ACCEPTS P11, - TWO WIRE
WRAP POSTS IN BACKPLANE
o
o

o
o

CZ·0276

Figure 2-16

Adapter Backplane (Lower Adapter)

Remove the· single-port jumper wire from
(wirewrap post) on the adapter backplane.

Install two MS923 modules in slots 1 and 2 (rows C-F) of
the card cage.

Install the new dual-port switch assembly in the upper
door hinge pin bracket. (Refer to Figure 2-17.)

2-36

connector

CABLE
CLAMPS
CABLE
CLAMPS

C2·0277

Figure 2-17
10.

Dual-Port Switch (Single Adapter)

Route the switch assembly cable.
a.

Install a tie wrap block on the chassis frame channel
about 14 inches from the bottom of the channel (refer
to Fig ure 2-16).

2-37

Route the switch assembly cable through the chassis
frame channel toward the adapter cabinet.

Place the cable through the tie wrap block installed
in step 10a.

Install a tie wrap block on the backplane about two
inches above the front corner of the backplane cover.

Route the switch assembly cable along the backplane,
through the tie wrap block installed in step 10d and
along the front of the backplane to the connectors
installed in step 6.

11.

Connect the 3-pin male plug to the female connector
installed in step 6. Note that the plug is keyed and can
only be installed one way.

12.

Connect the two 2-pin plugs to the connectors installed
in step 6. The plug labeled "A" goes to connector "A",
and the plug labeled "a" goes to connector "8".
Ensure
that the orange wire installed in the plugs is on the top
and the black wire is on the bottom.

13.

Install MASSBUS port a cables.

140

Install the port B MAssaus cable in the
cabinet following the same service loops
MASSBUS port A cable.

adapter
as the

Tie wrap
together.

cables

Connect MASSaUS port 8 cable to connector J7 (refer
to Figure 2-18).

Terminate
present) •

the

port

(or

A and

continue

port

B MASSBUS

adapter

Check the port switches.
a.

Power up the drive/adapter.

Install the disk pack and allow ~he pack to purge for
10 minutes. This is to allow the clean air system to
be purged of any contaminants induced during shipment
of the drive and pack.

2-38

POWEI:I

SEOuE"'CE
O..,'!

AC "OWEA
CABLE

GAOUNOING LUGS

Figure 2-18

MASSBUS Cable Routing (Dual-Port, Single Adapter)

NOTE
If unused packs are properly stored in a
clean envi ron.ent, they should not need
an extended purge prior to use.
c.

Select either port A or port
appropriate button/switch.

The button/switch will illumiCycle up the drive.
na te when the po rt is selected (heads must be
loaded).

2-39

B by depressing

the

Cycle down the drive.

When heads unload, select the other port switch.

9·

Cycle up the drive.
na te when the po r t
loaded).

If either port fails to operate, check the wiring and
connectors for possible malfunction.

The button/switch will illumiis selected (heads must be

15.

Slide the adapter to center position, guiding cables as
required.

16.

Install and close the front and rear doors.

2.4.10 Oual~Port Option (Upper RM Adapter)
Prepare the upper adapter cabinet for dual-port
shown below.
1.

Cycle down the
drive/adapter.

drive

Remove the front
cover plate.

door

(if

necessary)

installation as
and

power

and appropriate dual-port

off

switch

Unlock the door with an Allen wrench.

Remove the ground braid from the door.

Pull down the upper hinge pin (spring-loaded).

Li ft the door clear of the bottom hinge pin and set
aside.

Remove the appropriate dual-port switch cover plate
from the front of the cabinet and set aside.

Remove the rear door.
a.

Unlock the door with an Allen wrench (size 6mm).

Remove the ground braid from the door.

Li ft the door to clear the hinge pins from the hinge
brackets and set the door aside.

Push the adapter to forward stop on slides.

Check the adapter backplane for dual-port toggle swi tch
and two LEOs.
If installed, proceed to the next step.
If not, go to step 7. (Refer to Figure 2-19 for location
of switch and LEOs.)
2-48

51 (ACCEPTS P10)

PORT B LAMP POSITION
CACCEPTS P12) - TWO WIRE
WRAP POSTS IN BACKPLANE

PORT A LAMP POSITION
(ACCEPTS P11, - TWO WIRE
WRAP POSTS IN BACKPLANE

•••

•

-0
CZ·0216

Figure 2-19
6.

Adapter Backplane (Upper Adapter)

Toggle Switch and LEO Removal/Replacement.
a.

Unsolder the two LEOs and the toggle swi tch from the
backplane using a low wattage soldering pencil.

Install one 3-pin female connector in the
where the toggle switch was located.

Install the two 2-pin connectors in the positions
where the LEOs were located. The connector labeled
-A" should be installed on the left side of the
female connector and the connector labeled -B" on the
right side.

position

Remove the single-por t :jumper wi re from
(wirewrap post) on the adapter backplane.

Install two M5923 modules in slots 1 and 2 (rows C-F) of
the card cage.
2-41

connec tor

Install the new dual-port switch assembly bracket to the
front of the backplane support mount on the upper adapter
( ref e r to F i <:I ur e 2 - 20) •

Figure 2-20

Dual-Port Switch (Upper Adapter)

1~.

Install the switch assembly in
bracket on the upper adapter.

11.

Route the swi tch assembly cable along the front of the
backplane to the connectors installed in step 6 (refer to
Fig ur e 2 - 2 g) •

12.

Connect the 3-pin male plug to the female connector
installed in step 6. Note that the plug is keyed and can
only be installed one way.

2-42

the

switch assembly

13.

Connect the two 2-pin plugs to the connectors installed
in step 6. The plug labeled -Aw goes to connector "A" and
the plug labeled -8 w goes to connector -8".
Ensure that
the orange wire installed in the plugs is on the top and
the black wire is on the bottom.

14.

Install MASSBUS port 8 cables.
a.

Install the port B MASSBUS cable from connector J6 of
the lower adapter cabinet to connector J7 of the
upper adapter cabinet following the same service
loops as the MASSBUS port A cable.

Tie wrap
together.

Connect MASSBUS port B cable to connector J6 in the
lower adapter cabinet and to J7 in the upper adapter
cab in e t
( r e £e r to Fi 9 ur e 2 - 21 ) •

Terminate J6 in the upper adapter i£ it is the last
drive- in the series, or route a MASSBUS cable from
connector J6 to the next drive in 'the series (refer
to RM adapter cabling procedure earlier in Chapter

the

port

A and

port

MASSBUS

cables

2) •

15.

Check the port switches.
a.

Power up the drive/adapter.

Install the disk pack.

Select either port A or port
appropriate button/switch.

The button/swi t~h wi 11 ill urn iCycle up the drive.
nate when the port is selected (heads must be
loaded) •

Cycle down the drive.

When the heads unload, select the other port switch.

Cycle up the dr ive.
na te when the po'r t
loaded).

I£elther port fails to operate, check the wiring and
connectors for possible malfunction.

B by depressing

the

The button/switch will illurniis selected (heads must be

16 •

S1 ide th e ad apt e r to th e c e n t e r po sit ion, 9 u i din g cab 1 e s
as required.

17.

Install and close the front and rear doors.

2-43

OCPOWE~RJL1-~~--f===~~~--~~
IN

TIE WRAP

GROUNDING LUGS
110 CAlLES

Figure 2-21

MASSBUS

Cable Routing (Dual-Port, Two Adapters)
2-44

cz·_

2.4.11 Cabinet Leveling
Cabinet leveling should not be performed until the drive is in the
desired location and there is no further need to move it. (Refer
to parag raph 2.2.1, steps 8a and 8b).
Cabinet leveling consists of installing leveling pads, placing the
drive in the desired location, screwing down the 'leveling pads
until the drive is aligned with other cabinets, and ensuring that
the weight Is off the casters.
1.

,Install t.he jam nut on each leveling pad. Then install a
level ing pad at each corner of the cabinet frame (see
Figure 2-22) by raising the corner of the cabinet and
threading the leveler into the weldnut on the frame.
WELDNUT

NOTE
CASTERS AND LEVELING LEGS
ARE LOCATED AT EACH
CORNER OF FRAME

Figure 2-22
2.

Cabinet Leveling

Place the drive and adapter in the desired location.

2-45

Turn the leveling pads down until they support the entire
weight of the drive and adapter.

Adjust the leveling pads until the drive and adapter are
aligned with adjacent equipment.

Place a spirit level on the cabinet 'top cover and adjust
the leveling pads until the cabinet is level within three
angular degrees both front-to-back and side-to-side.

When the cabinets are level in both directions, tighten
the jam nut against the bottom of the frame.

2.5
INITIAL CHECKOUT AND START-UP
Th is proc ed ure de sc r i bes chec ks tha t sho uld be pe r fo rmed on the
drive prior to putting it on-line.
This procedure assumes that
the drive has been unpacked, installed in its normal operating
position, that all grounding, power, and I/O connections have been
made, and that the proper logical address plug has been installed.
2.5.1

Drive Power-Up

Set all circuit breakers OFF.

Perform the ·clean shroud and spindle· procedure
to RM~5 Disk Drive Service Manual).

Open the cabinet rear door, release the
catch and swing the logic chassis open.

Remove the logic chassis card cover and verify that all
cards are firmly seated in their connectors.

Verify that all connectors are firmly seated on the backpanel pins, and check for loose or broken wires.

Open the top cov~r and remove the deck cover.

Verify that all cards in the read/write
firmly seated in their connectors.

Set all circuit breakers to ON, verify that the blower
starts and allow it to operate for at least l~ minutes
before proceeding to step 9.

(refer

log ic chassis

chassis

are

Install the scratch disk pack, and ·allow it to purge for
minutes.

NOTE
If unused scratch pack is stored in a
clean environment, it should not need an
extended purge prior to use.
2-46

1e.

11.

Press the START switch and verify that the actions listed
below oce ur •
a.

The START indicator lights.

The dr ive motor starts, "and the
speed in approximately 30 seconds.

The heads load when the pack comes up to speed.

pack

comes

Perform the procedures listed below.
a.

Servo system test and adjustments

Head alignment

2.5.2
Tests and Adjustments
Perform the servo system test and adjustments using either microdiagnostic test routines (test software) or the TB3A2 field test
unit (FTU).
2.5.2 1
Testing Wi th Software - Testing wi th softwa re requ ires
the use of a controller and the appropriate software.
In this
type of testing, the drive communicates with the controller as
during normal on-line operations and no special I/O connections
are necessary.
D

Except" for I/O connections, the" procedure for prepar ing the drive
is the same as that used when testing with the""PTU. See paragraph
2.6.3 for software test routines used for initial checkout.
2.5.2.2
Preliminary Setup - Use the procedure given
prepare the drive for initial checkout testing.
1.

below

Press START switch to stop the drive motor and unload the
heads.

NOTE
Disable I/O by deselecting the drive at
the controller before performing step 2.

NOTE
All procedures other than the head
alignment require installation of a
scratch pack.
However, head alignment
requires a CE pack.
2.

Raise the pack access cover, remove the customer disk
pack, and replace it with either a scratch pack or CE
pack for head alignment only.

Close the pack access cover.

2-47

Open the rear door and set the MAIN AC circuit breaker to
OFF.

Release the logic chassis latch and open the chassis.
NOTE
If the test software Is to be used,
proceed to step 8.
If the FTU is used
with th~ standard
IIO connection,
proceed to step 6.
CAUTION
Do not damage the cables between the I/O

panel and the logic chassis or system
I/O cables when performing step 6.
6..

Connect the FTU standard I/O cables
described below (see Figure 2-23).

the

drive

Turn the I/O panel fastener counterclockwise and
remove the panel from its upr ight support.
Thi s
allows the panel to be posi tioned so the cables can
easily be installed.

Remove the hardware secur ing the I/O panel cover to
the I/O panel and remove the cover and set it aside.
The cover is not replaced until the maintenance is
complete.

Disconnect the I/O cables from J2 and J3 on the drive
I/O panel.

Install the tester cable A to J3 and B cable to J2.

Position the I/O panel on its upright
secure with the I/O panel fastener.

If the drive is in the daisy-chained system, make
necessary connections to ensure other drives remain
under system control.

support

and

Loosen the turn-lock fastener secur ing the card
cover to the logic chassis and remove the cover.

Install the card extender if the test or adj ustment
procedure being performed requires· it.
This requirement
will be noted in that procedure.

If the head alignment is being performed,
described below.
If not, go to step 10.

proceed

Install

the

head

alignment card

Al6.

2-48

(HFSV)

cage

location

REAR DOOR

FTU---"""

Figure 2-23
b.

Standard FTU to Drive I/O Connections

Connect the head alignment cable from the logic
backpanel locat 10n Al6, pins 8 through 11, to J 1 on
card E03 in read/wr i te chassi s.
(refer to parag raph
2.4.3 for more informatioti.)

1D.

Set the MAIN AC circuit breaker to ON.

11.

If using the FTU, set the SEC (sector) switch on the FTU
panel to 32.

2-49

12.

Set the following switches on the FTU as shown below.
Switch

position

SEQ PWR

SERVO OFFSET

Center (OFF)

DATA STROBE

Center (normal)

WRT FLAG

Down (OFF)

XTAL/SERVO

SERVO

Switch

Position

SEQ PWR

SERVOOFFS'ET

Center (OFF)

DATA STROBE

Center (normal)

WRT FLAG

Down (OFF)

XTAL/SERVO

SERVO

MAINT/NRM

NRM

WRT INHIBIT/NRM

NRM

PLUG VALID

UNIT (three switches)

Logical address of drive

ADDR ERROR/BYPASS
(2 switches)

Both switches down (OFF)

13.

Turn on the FTU.

14.

Press the START switch to the start drive motor and load
the heads.

15.

Select the drive.
When the drive is selected,
ready for tests and/or adjustments.

16.

Actuate the INITIALIZE switch.

17.

Actuate the RTZ switch, then the RESET switch.

2-51

The drive is now ready for exercising. It has performed a seek to
cyl inder e and has selected head 8.
If you are testing wi th the
FTU, you may now set the switches on the PTU control panel to
exercise the desired functions and operating modes.
The
paragraphs below describe these procedures when using the FTU.
2.5.3

Head Alignment Procedure

2.5.3.1
Installation of the Bead Aligment Card - This procedure
descr ibes ·the use of the HFSV head al ignment card and the null
meter on the FTU control . pane.l to perform read/wr i te and servo
alignment.
Figure 2-24 shows the cabling involved, and Figure
2-25 gives specific connection information. Figure 2-25 shows the
switches and indicators on the HFSV card.
This procedure assumes that the I/O connections between the drive
and the FTU are as described in paragraph 2.5.2.2.
Remove the ac
power from the drive and FTU before installing and cabling the
head alignment card.
1.

Insta 11 t.he HFSV card in the log ic chassi s in the d rive,
at location A16.

Install ·the head aligment .cable between the 'log ic chassi 5
in the drive and the jack on the card in the read/write
chassis, as specified in Figure 2-24.
P104 is keyed so
it will fit on the read/write card only one way.

Connec t t.he test lead s prov ided wi th the FTU between the
HFSV card and the null meter on the FTU panel.
Observe
the polarity.

Set the WRT INHIBIT/NRM switch on the fTU to WRT INHIBIT.

Apply ac power to the drive.
card should light up.

Install the proper CE pack on the dr ive to be tested.

Power up the dr ive.

Turn on the FTU.
If the drive under test is in the
write-protect mode, the WRT PROTect light on the FTU will
be lit.

When the dr i ve is up to speed and the READY 1 ig ht on the
FTU panel is lit, actuate RESET, then RTZ.

10.

Set the MAINT/NRM switch to MAINT.
This provides a
pseudo-index mark that enables the FTU to generate a head
select.
(The CE pack does not have an index mark.)

2-51

The POWER lamp on the HFSV

P10-'

INDICATORS
(NOT ON NEWER CARDS)
HEAD
SELECTIREAD
AMPLIFIER CARD
E03
HEAD ALIGNMENT
CAlLE

---L

A 16 DISK DRIVE
LOGIC CHASSIS

LOGIC CHASSIS
WIRE WRAP PINS

FIELD TEST
UNIT

NOTE
USE TOP SCALE OF FIELD TEST UNIT
METER IN CONJUNCTION WITH S3

S3 POSITION
Xl

X.1

Figure 2-24

FULL SCALE READING
-100 MV TO
-1.0 MV TO

+100 MV
-1.0 MV

Head Alignment Connections

2-52

CZ·03II

o POWER
INDICATORS

{

SEE NOTE 3
51

0 INPUT
0 BAD TRK
o MODE
P
N COMPONENT
S SIDE OF
RWCARD

_fSV CARD
HEAD SELECT I
READ AMPLIFIER
CARD
E03

SEE NOTE 2

X1
HEAD ALIGNMENT
CABLE
CONNECTS TO PINS
8 THROUGH " , A AND B

LOGIC CHASSIS
WIRE WRAP PINS

f'~.o~50

SEE NOTE 1

.1.

NULL METER

50· 500

Figure 2-25
11.

Table 2-2

NOTES
,.

2.
3.

METER IS PART OF FTU OR HEAD ALIGNMENT KIT.
METER READINGS TO LEFT OF ZERO ARE NEGATIVE
AND READINGS TO RIGHT OF ZERO ARE POSITIVE.
NEWER KITS HAVE _ ZPV.
INDICATORS 00 NOT APPEAR ON _ ZPV CARD.

CZ·02&4

Head Alignment Card

Allow the drive to thermally stabilize on cylinder 0 for
60 minutes (see paragraph 2.4.3.2).
NOTE
Installing the bead allignment .. card
(Table
2-2)
automatically
writeprotects" the drive, lIven though it vill
not cause the WRT PROT light to come on.
The HFSV card must first be removed from
the drive if write, write then read, or
write format operations are to be
conducted.
Head Alignment Card Switches' Indicators

Switches

Description

Changes the polarity of the alignment signal
to the null meter:
p . posi tive, N =
negative. Algebraically subtract N from P to
de te rm ine al ignment er ror.
If P • +30 mV and
N • -40 mV, the error is 70 mV.
S position selects servo head as input to
HFSV.
RW posi t ion selects a data head as
input to HFSV.

2-53

Table 2-2

Head Alignment Card Switches, Indicators (Cont)

Switches

Description

Changes sensitivity of HFSV. The X.l position
attenuates the card output by a factor of 10,
and alignment errors cannot be accurately measured.
The Xl position does not attenuate
HFSV output and alignment errors can be
accurately measured.

Indicators

Description

POWER

Lit when power is applied to the card.

INPUT

When lit, indicates that input signals are too
low for HFSV to operate.

BAD TRK

When lit, indicates a short duration loss of
input.
The lamp will light when 51 is toggled.

MODE

Li t when 52 is in the 5 (servo) posi t ion or
when 53 is set to X.l.
When either condition
exists, read/write head alignment error cannot
be measured.

2.5.3.2
Preliminaries for Head Check or Alignment - Read and understand the concepts that follow before performing the head arm
alIgnment procedure.
They are important for accurate head
al ignment.
Thermal Stabilization - It is important that the .drive, CE pack,
and FTU be at their normal operating temperature to ensure accuracy during head alignment.
This requires that all three be
connected and allowed to operate (pack turning and heads loaded to
cylinder 0) for a minimum of 69 minutes.
If head ali~nment is
being performed on more than one drive, subsequent drlves need
only 15 minutes for stabilization if the pack is taken immediately
from a drive on which it had been operating for 6" minutes.
Write-·Protect - Although the presence of the head alignment card
in the appropriate slot will write-protect the drive, the WRITE
PROTect switch on the front of the drive should be pushed in as an
added precaution.
Alignment Tool - Use only the head alignment tool specified.
Use
of a different tool may cause damage to the head-arm or carriage.
Al ways inspect the adj ustment. end of the tool pr ior to use.
The
tool must be free of nicks and scratches and must have a polished
sur face.
If any aluminum deposi ts are present, pol ish. the tool
surface with a crocus cloth.
Any other polishing medium will
damage the tool.
2-54

Do not use a defe'ctive tool. Repair or replace the tool if it is
damaged.
When using the tool, position it so the pin in the end
of the tool engages the adjustment slot in the head arm.
Ensure
the tool is kept perpendicular to the hole in the carriage at all
times. The tool should turn freely in the hole.
If it does not,
recheck the end of the tool for damage or aluminum buildup.
Calculating Offset - "The formula for calculating head offset is
(P) - (N) • offset, where P is equal to the meter read ing wi th the
head alignment cardP/N switch in the P position, and N is equal
to the reading with· the switch' in the N position.
All meter'
readings to the left of " are negative.
Some examples. of offset
calculation are given below.
1.

P = +20 nnV, N • +15 mV
(P) (N) • (+20) - (+15) - +5 mV

p . +20 mV, N = -15 mV
(P) (N) • (+20) - (-15) • +35 mV

P = -20 mV, N • +15 mV

(P) (N) • (-20) - (+15) • -35 mV
Seek Error Prevention - When the alignment tool is used to position the·heads, a small amount of 'sideway pressure'on the tool can
cause the carriage to move.
This relatively minor amount of
movement generates an error voltage which is sensed by the logic
as a seek error.
The resul t is that. the log ic clears the slope
flip-flop and causes the drive to seek to the next even cylinder.

Excessive Misalignment - Occasionally during the alignment check,
a badly misaligned head (in excess of 300 mV offset) may be discovered.
When this occurs, do not realign the head until all
packs written by that drive have their data tz::ansferred to other
storage.
Fail ure to dump the packs before realignment will mean
that the data written by that head is not recoverable.
Carriage Locking ,- During the alignment procedure (when the heads
are 0 v e r th e a I i g nm e n t t r a c k), th e car i i ag e 10 c king pin and r in 9
assembl y is installed in the ALIGN TRACK LOCK hole in the ra i 1
bracket assembl y.
Th i s locks the carr iage in place.
Fa i I ure to
install the pin and ring assembly allows the carriage to retract
if ·an emergency 'retract signal is generated. If your hands are in
the actuator during the head alignment procedure, the retract
could be dangerous.
It should als,o be noted that if a retract
condition is generated, the carriage locking pin and ring assembly
must be removed immediately to allow the heads to retract before a
head crash occurs.
Carefully observe the instructions regarding
the installation and removal of the carriage locking pin and ring
assembly.

2-55

NOTE
Do not do an RTZ on the rTU wi tb the
carriage locking pin in the ALIGN TRACK
LOCK hole.

2.5.3.3
Initial Setup head al ignment.

Use the procedures given below to check

Connect the FTU to
paragraph 2.5.2.2.

the

drive

using

the

procedures

Ensure that the CE pack is thermally stabilized.

Connect an oscilloscope to test points Z (ground)
(dibits) on the head alignment card.

Connect the test leads between the head al ignment card
and theFTU null meter as shown in Figure 2-25.

and 'l

2.5.3.4
Servo Head Alignment Check - Use the following procedure
to check the alignment of the servo head.
1.

Set the head al ignment card S/RW swi tch to Sand X.l/Xl
s wit c h to X. 1.

Command continuous seeks between cylinders 360 8 and 365 8
for a minimum of 39 seconds.

Command direct seek to cylinder 004.

4..

Observe the dibit pattern on the oscilloscope.
be similar to that shown in Figure 2-26.

It should

NOTE
At X.I swi tch setting, the upper scale
of the PTU meter is read X191 (or + 1. I
V); at Xl switch setting, the upper'
scale is read XII (or + leI mY).
5.

Move the P /N swi tch to both P and N posi t ions and reco rd
the null meter readings.
If both P and N readings are
less than 199 mV, the X.I/XI swi tch can be set to Xl
position for more accurate readings.

Calculate
below.

the

head

offset

(P) -

(N)

using

= OFFSET

Record the offset calculated in step 6.

2-56

the

formula

given

OSCILLOSCOPE SEmNGS
LOGIC GND TO SCOPE GND
VOLTS/DIV
CH1 -0.1 V
CH2 - NOT USED
TIME/DIV
A - 0.6 ".S
8 - NOT USED
TRIGGERING
A - INTERNAL POSITIVE
8 - NOT USED
PROBE CONNECTIONS (USE )(10 PROBE)
CM1 TO DIBITS TEST POINT YON HD ALIGN CARD
CM2 - NOT USED
A

•

:... ::...~.. /.=...::...::...::...::.-.::...::...:
.~

u
. 'r~

'·1

. .

CH I

.
CH2
·..1.. J..... ···... "r ... ·~ ..... J. .. -.. ·· ....... ···
I-

-:~

-,-_ _ _ _ _ _ _._--I-I- .. _ _ _ _ _ _ _ _ _ _~~.~\~
~ _ _ _ _ _ _~ _ _ _ _ _ _- J

Figure 2-26
8.

Balanced Dibit Pattern

Evaluate the servo head offset as described below.
o

If the offset ranges between +60 mV and -60 mV, it is
acceptable; proceed wi th head al ignment.

If the offset is outside of +60 mV range, it is
unacceptable.
In this case, troubleshoot the servo
system before proceeding with the head alignment.

Command the direct seek to cylinder OOS and repeat steps
4 through 8.
2-57

l~.

Add the offset readings from cylinders 004 and 005. This
sum should be between. +75 mV and -75 mV.
If it is not,
troubleshoot the servo system.

11.

Command the direct
steps 4 through 8.

12.

Command the direct seek to cylinder 7538.

13.

Install the carriage locking pin into the al ignment hole
(refer to Figure 2-27 and repeat steps 4 through 8).

seek

cylinder

140~8

and

repeat

EQUAL
LOCKING PIN
SHIPPING HOLE
LOCKING PIN
ALIGNMENT HOLE

LOCKING PIN
STORAGE HOLE

ACTUATOR
HOUSING

CAUTION
ALIGNMENT TOOLS ON SOME DRIVES
CANNOT BE ROTATED MORE THAN
1500. ROTATING TOOL BEYOND 1500
MAVDAMAGEHEADORTOOL

HEAD-ARM
CARRIAGE

Figure 2-27

Head-Arm Alignment
2-58

This completes the servo head alignment check procedure.
Now
proceed with the read/write heads alignment check and adjustment.
2.5.3.5
Read/Write Beads Alignment Check and Adjustment - Use
the procedure given below to check the alignment of the read/write
heads and adjust those out of tolerance.

Set the S/RW switch on the alignment card to RW. Observe
that dibi t pattern is similar to that shown in Fig ure
2-26.

Calculate the offset of all
procedure given below.

read/write heads 'using

the

Move the PIN swi tch to both P and N posi ti'ons and
record the null meter read ings.
If both P and N
readings are less than 100 mV, the X.l/Xl switch can
be set to the Xl position for more accurate readings.

Calculate the head offset by using the formula given
below.
(P)

-. (N)

•

OFFSET

Remove the carriage locking pin.

Evaluate the read/write head .offset as described below.
o

If all offsets are between +150 mV and -150 mV, head
alignment is within specifications.
In this case,
proceted to step 15 and restore the dr ive to on-l ine
operation.

If any offsets are .outside of the +150 mV range,
the heads are mi sal 19ned.
Proceed to step 5.
However, before proceeding, ensure that no offset
exceeds a +300 mV range.
If any offsets exceed this
range, excessive misalignment exists. . Refer to the
RM0S Disk Drive Service Manual for steps to take in
the case of excessive mIsalignment.

Press the START switch to stop the drive motor and unload
the heads.

Loosen the head-arm mounting screws secur ing the heads
requi ring al ignment and torque these screws to 4 ±,1/2 in
lbs (0.5 !0.1 Nm).

Press the START switch to start the drive motor and load
the heads.
Before proceeding to step 8, set the
MANUAL/SEQ swi tch of the FTU to MANUAL and set the
desired head selection In the H~D ADDR REG switch.
2-59

Command the direct seek to cylinder 7538.

WARNING
Power Is on.

NOTE
The force exerted dur ing adj ustment can
move the heads from the alignment
cylinder to an adjacent cylinder,
resulting in an improper alignment.
Prevent this by connecting a jumper from
A07-llA (seek error) to ground. Be sure
to remove the jumper before commanding
the drive to perfor. another seek.

Align the heads as described below.
a.

Select the head to be aligned.

WARNING
To prevent personal injury in case of an
emergency retract, install the carriage
locking pin in the alignment track lock
hole prior to positioning the head
al ignment tool.
Be sure to remove the
pin before the next seek is performed.
b.

Install the head al ignment tool so that the tool pin
engages the head-arm a1 ignment slot (refer to Figure
2-27) •

Observe the oscilloscope and adjust the head to
obtain a balanced dibit pattern.
The pattern is
balanced when point A amplitude equals point Band
point C' equals point 0 (see Figure 2-26).

Observe the null meter and adjust the head until the
offset ranges between +75 mV and -75 mV.
Calculate
the offset as described in step 2 above.
The offset
values should be in the +150 mV range. Occasionally,
a head cannot be a1igned- because its adj ustment slot
i sat its end 0 f t r a vel.
1 f this 0 c cur s, c h ec k the
posi tion of the servo head-arm adj ustment slot and,
if necessary, recenter it.
Note that any slight adjustment of the servo head
requires realignment of all read/write heads. Torque
the servo head to 12 +1/2 in 1bs (1.4 +0.1 Nm).
While torquing screws, use only a straight:arm Allen
wrench and keap it as perfectly aligned as possible
wi th the screws.
If care is not taken dur ing this
operation, the head may be pushed out of alignment.
2-60

Repeat steps a through d for each bead to be aligned.

10.

Remove the carriage locking pin and also
jumper from A07-11A if it was installed.

remove

the

11.

Press the START switch to stop the drive motor and unload
the heads.

12.

Torque the head-arm clamp screws of each head adjusted to
12 +1/2 in lbs (1.4 +0.1 Nm). While torquing screws, use
only the straight-arm Allen wrench and keep it as
perfectly aligned as possible with the screws. _

13.

Check each head adjusted to see if torquing the screws
affected the alignment.
If any heads are outside the
±150 mV range, readjust them as in steps 6 through 12.

14.

Perform the actions listed below to en~ure that the heads
will remain aligned under normal operating conditions.
a.

Command continuous seeks between cyl inders 3608 and
36S8 for a minimum of 30 seconds.

Unload and load heads at least twice.

Command the direct seek to cylinder 7538.

d. -Allow the drive to thermally stablize for at -least 15
minutes.
e.

IS.

Check the al ignment of each head adj usted.
If any
heads are outside the +150 mV range, repeat this
procedure starting with step 9.

Prepare the drive for return to on-line operation.

2.5.4
Servo System Tests and Adjustments
These procedures test and adjust the drive servo system. The servo system adjustments and their basic functions are as described
below. (Refer to Figure 2-28).
o

Coarse Posi tion Gain - Adj usts the gain of the veloc i ty
_sign-al applied to the summing amplifier when the servo
system is l.n coarse mode (cylinders-to-go equals more
than one-hal f) •
This adj ustment causes seek-time to be
fast enoUlgh to meet the required specifications without
causing excessive overshoot past the desired cylinder.

Integrator Gain - Adjusts the gain of the velocity signal
applied to the integrator. The integrator output is summed with the output from_ the D/A converter during the
last 128 cylinders of a seek.

2-61

PERFORM
COARSE POSITION
AIN ADJUSTMEN
PROCEDURE

PERFORM
INTEGRATOR
AIN ADJUSTMEN
PROCEDURE

PERFORM
FINE VELOCITY
AIN ADJUSTMEN
PROCEDURE

YES
NO
SERVO
ADJUSTMENT
PROCEDURES
COMPLETE

RECHECK COARSE
POSITION GAIN
ADJUSTMENT

YES

CZ·02II

Figure 2-28

Servo System Test and
Adjustment Flowchart

2-62

Fine Velocity Gain - Adjusts the gain of the velocity
signal appl ied to the summing amplifier when the servo
system is in fine mode (cylinders-to-goequals less than
one-hal f) •
This adj ustment optimizes the servo system
response by minimizing overshoot without overdamping the
system.

These adjustments are interactive and must be made in the sequence
shown in Fig ure 2-29.
The proced ure given below descr ibes the
test and adjustment of the servo system.

OSCILLoscope SETTINGS
LOGIC GND TO SCOPE GND

LOST DISCONTINUITY

VOLTS/OIV
CH 1·0.6 V/CM
eH 2· NOT USEO
TtME/OIV
A - 0.6 MS/CM
B - NOT USEO

FWD

SEEK

HORtZ DISPLAY
SET TO MAG X 10

TRIGGERING
A - POSITIVE EXT ON A'12·17B (+TS7)
B - NOT USEO

~~--~~--~~~~--+-~--~~REV

SEEK
PROBE CONNECTIONS
CH' TO A20·TPO (+ DESIREO VELOCITY)
CH2 - NOT USEO
NOTE
IT IS NECESSARY TO INCREASE
VERTICAL SENSITIVITY TO MAKE
THIS MEASUREMENT.

SECOND TO LAST DISCONTINUITY

<30MV

.~
OK

IDEAL

OK
CZ'02S7

Figure 2-29
1.

Integrator Gain Waveform

Prepare t.he drive using 1the preliminary setup procedures
given in paragraph 2.5.2.2.

2-63

Test and
below.

adjust

the coarse

position gain as

described

Command the continuous seeks between cylinder 000 and
14*568.

Connect the oscilloscope channel
CYLINDER) •

Trigger the oscilloscope negative external on A07-07A
(FORWARD SEEK).

Set other oscilloscope controls as necessary to make
measurements required in step e. (2 volts, 10
milliseconds) •

e.'

Observe the display_
If the distance between
on-cylinder
pulses
is
not
within
50
to
54
milliseconds, adjust top potentiometer on card A20
until this requirement is met.

1 to A07-03A

(+ON

Test and adjust the integrator gain as described below.
a.
b.

Command the continuous seeks between cyl inders 000
and 2008.
Set up the oscilloscope as indicated in Figure 2-29.
Adjust it until the two sloped curves are displayed.
NOTE
VOLT/CM and TIME/eM settings have to be
changed to make measurement required in
step c.

Observe the second to last discontinui ty (indicated
in Figure 2-29) and check to see if it has a
Ig no r e the s pi ke •
If i t
d iff ere nc e 0 f + 0 • 03 V_
exceeds this value, adjust the bottom potentiometer
on A20 so that it meets these requirements.
NOTE
In step 4, the read operation is performed between seeks.
This causes
enough delay between seeks to provide
the proper display.

Adjust the fine velocity gain as described below.
a.

Set MANUAL/SEQ switch on FTU to MANUAL.

Command the read operation to be performed in
conjunction with continuous seeks between cylinders
£'1£'10 and 001.

2-64

Connect and aet up the osc illoscope as ind icated in
Figure 2-38.

OVERSHOOT ~
UNDERDAMPED

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GND
VOLTS/DIV
CH1 - O.6V/CM
CH2 - NOT USED
TIME/DIV
A -- 1 MS/CM
B - NOT USED
TRIGGERING
A - NEGATIVE ON A07·30A
(-SEEK)
B - NOT USED
PROBE CONNECTIONS
CH1 TO A19·TPC
(+ FINE POSITION ANALOG)
CH2 - NOT USED
UNDERSHOOT

CZ·02SE

Figure 2-38

Fine Velocity Initial Check Waveform

Referr ing to Figure 2-30, note that the displayed
signal settles with maximum overshoot of less than
50 mv.
If the overshoot exceeds this val ue, adj ust
the middle potentiometer on card A20.
When the adjustment is complete, the display should resemble the
ideal waveform in Fig ure 2-30.
A 61 ight undershoo t
is desirable.

Command the sequential forward seek from cylinder 000
through 14668 to be per formed in conj unct ion wi th a
read ..
2-65

Note that a displayed signal is shown in Figure 2-31
at each cylinder. If the overshoot exceeds 50 mv at
any cylinder, adjust the middle potentiometer on card
A20 until this requirement is met.
OSCILLOSCOPE SEUINGS
LOGIC GND TO SCOPE GND
VOLTS/DIV
CH1 - O,BY/CM
CH2 - NOT USED
TIME/DIY
A • 0.1. MS/CM
B - NOT USED
TRIGGERING
A - EXT, A07·30A (-SEEK)
B - NOT USED
PROBE CONNECTIONS
CM1 TO A19·TPC (+ FINE POSITION ANALOG)
CM2 - NOT USED

)~~
-

- ~

I-'"

-- -

-...

tIII_ - - -

I-

J \ . ........
~P"

"'-...,..

..........-:~

r"""~

lIlI-

-..... - ----- - --_. ---- -- -- --- ---- ------ .. - --- - -- -_.. _..

I-

-I-

I-

-I-

-,,",

I-

cz·om

Figure 2-31
5.

Fine Velocity Gain Overshoot

Prepare the drive for return to on-line operations.

2.5.5
Operating Procedures
The procedures below check all access, read/write, and head select
modes.
Additionally, these procedures check the data error logic
circu:Lts.

2-66

2.5.5.1
Continuous Seek, No Read/Write - This procedure performs
alternate seeks between the cylinder address in the cylinder
address register (CAR) and the address set in the CYLINDER ADDRESS
switches.
1.

Position
2.4.2.2.

the
The~,

PTU switches as described i,n paragraph
position the switches below as indicated.

Switch

Position

DISPLAY SELECT

CYLINDER

WRT-RD SELECT

OFF

Set the CYLINDER ADDRESS switches to the value of a cylinder to which the drive is to seek.

Set the ACCESS MODE switch to DIRECT.

Momentarily actuate the START switch on the FTU.
When
the ON CYL indicator on the FTU is lit, move the START
switch momentarily to STOP. The cylinder address loaded
in step 2.should now be displayed on the cylinder address
display lights.

Set the CYLINDER ADDRESS switches to the value of some
second cylinder address.

Set the ACCESS MODE switch to CONT.

Actuate START.
The drive will perform al ternate seeks
between the two cylinder addresses loaded in steps 2 and
5. The ON CYL ind ica tor will blink rapidl y as the head s
The cylinder address
move on and off the cylinder.
display lights will alternate between the two addresses.

Set the START switch to STOP.

Actuate RTZ.

10.

Actuate START. The sound o.f the drive will change as it
now seeks between cylinder " and the one loaded in step
5 •. Observe the ON CYL arld cylinder address displays.

11.

To stop the operation, actuate either STOP or RESET.

2.5.5.2 Random Seek, 110 Read/Write - Use the procedure
below to cause the drive to perform random seeks.

2-67

given

Maintain the preliminary setup switch positions.
dition, set the switches listed below as shown.
Switch

Posi tlon

DISPIAY SELECT

CYLINDER

WRT-RD SELECT

OFF

ACCESS MODE

RAND

Actuate START.

Watch the changing pattern on the display to
that the cylinders are being selected randomly.

Stop the FTU by actuating STOP or RESET.

In ad-

ensure

NOTE
After an FTU write-format operation, the
pack must be re-formatted using the
formatter program prior to running a
MAINDEC diagnostic program.
2.5.5.3 Write-Format - The procedure given below \'Iill write a
prescribed format on every track of the disk pack.
1.

Maintain the switch positions given in the preliminary
setup proced ure.
In add i t ion, set the swl tches 1 i s ted
below as shown.
Switch

Position

DISPLAY SELECT

READ DATA

ACCESS MODE

SEQ FWD

WRT-RD SELECT

WRT FORM~T

CYLINDER ADDRESS

All down (OFF)

SEQ/MAN

SEQ

HEAD ADDRESS

All down (OFF)

DATA PATTERN

70 octal "( any non-zero number)

Move the RTZ/RESET switch to RESET, then RTZ.

Actuate START.
Observe the progession of the display
lights as the drive moves away from cylinder 0. With the
DISPr.AY SELECT switch set to READ DATA, the cylinder
address is displayed while the FTU is running.
2-68

If an error stop occurs, remove the cause of the error by
proceeding as indicated in the trouble analysis chart in
Table 2-3.
Data errors will not occur during WRT
FORMAT. Then proceed as described below.

Table 2-3

Decision Logic Table

Assume:
I.
2.
3.
4.
5.
6.

A" B 110 cables connected between drive and FTU.
Power appJied to FTU and drive.
+ 5 V indicators on FTU panel are lit.
OAT AI ADDRESS !BYPASS switches OFF.
FTU set to READ nack format.
READ indicator comes on when START switch (on FTU panel) is actuated.
2

Conditions

Seek error
Clock error in SERVO position
Clock error in XT AL position
Sector Mark Error
Sector Count Error
Drive Fault

- - - - - Y - - - - - - - N Y - - N - - - - Y - N - - - - Y -y
N - - - - - N
N

Attions

Go to sheet 2. "Conditions."
Actuate RESET. RTZ. START.
Refer to drive service manua1.
Set XTAl-SERVO switch to XTAl:
Actuate RESET. START.
Check TP5 (\\'RITE ClK) on FTU pane1.
Refer to FTU diagrams.
Check B-cable for SER VO ClK signal. Troubleshoot
discontinuity in drive. cable. FTU.
Check that sector switch (SEC) in FTU is set correedy.
Check TP I (SECTO R MK) on FlU panel.
Checlc TPO (INDEX M K) on FTU panel.
Upper-left Quadrant:
Upper-Right Quadrant:
Lower-left Quadrant:
Lower-Right Quadrant:

- - - - - - - I - - - - - I

- 2 - - - 4 4 1
- - I - - - - - - - - 1 -5 -5 - - - - 2
- - - I - - - - - - - - - - - - - - - -

1
2

Assumptions needed for tests. as well as the test conditions.
Results of the test: N 8: No; Y &: Yes; - &: Don't care.
Actions to be taken for each test result.
Numbers show sequence of actions for the test results in a given column.
After each action. the test is repeated and. if X &: a Uno error" or "problem solved situation.
H

2-69

Table 2-3

Decision Logic Table (Cont)

Conditions

Address error

Data error. OFFSET and DATA STROBE switches in center (off) position

- Y

- -

Actions

Track was read without error.
Perform WRT FORMAT for track in error; READ rewritten track.
Perform WRT.RD retry as follows.

- I - - I

Set FTU switches as indicated below.
Switch

Posidon

WRT-RDSELECT
ACCESS MODE
SEQ/MAN
HDADRS
CYL ADRS

WRT.RD
DIRECT
MAN
Select
Failinl track

Actuate START; check fQr conditions II or 12 on followinl pale of table.
Unrecoverable error. Perform WRT FLAG procedure for track in er,·or.

2-70

Table 2-3

Decision Logic Table (Cc)nt)

Conditions
Data error on WRT.RD retry
Data error~ OFFSET switch in + (FWD) position
Data error. OFFSET switch in - (REV) position
Data error. DATA STROBE switch set
EARLY
Data error. DATA STROBE switch set
LATE
Actions
Set OFFSET switch to + (FWD) position;
READ track in error.
Check Bit 2 TP on FTU panel; if missing. refer to FTlI diagrams.·
Check B082 in drive: if missing. check I/O
cahle and F\VD offset logic in drive.·
Set OFFSET switch to' - . (REV) position;
READ track in error.
Check Bit 3 TP on FTIJ panel: if missing. refer to FT U diagrams.·
Check BOB3 in drive: if missing. check I/O
cable and REV offset logic in drive.Return OFFSET switch to center (off); set
DA TA STROBE switch to EARLY: Read
track in error.
Check Bit 7 TP on FTU panel: if missing. rt·
fer to flU diagrams.·
Check B087 in drive: if missing~ check I/O
cahle and Early Strobe logic in drive.Set DATA STROBE switch to LATE; Read
track in error.
Check Bit 8 TP on FTU panel~ if missing. refer to flU diagrams.·
Check BOB8 in drive: if missing. check I/O
cable and late Strobe IOJic in drive.·
Drive has demonstrated its ability to recover
data.
Unrecoverable error. Perform WRT FLAG
procedure for track in errolr.

- - - - - - - - - N Y - - - - - - - - - N Y - - - - - - - - - N y - - - - - - - - - N y
N

- - - - - - -

- I - - - - - - - - 2 - - - - - - - - .3 - - - - - - - - - - I - - - .- - - - c_ 2 - - - - - - - - 3 - - - -

- - - - - - 1 - - - - - - - - 2 - - - - - - - - 3 .. - - - - - - - - - I
- - - - - - - - - 2
X
- X - X - X - X - - - - - - - - - 3
-

·When checkini fl)f the pre~enCf of these bits. the DATA ERROR BYPASS switch must be on ("up" position). This allows
readini! ttl continue in the event or an error. The switch should be off ("down" position) when chcckinl for the conditions.

2-71

Actuate RESET to clear
FTU.

the error

ind ication

Actuate START.
This rewrites the track that was
selected when the error occured, then continues the
write-format operation.

Do not actuate RTZ.
To do so will cause the operation to begin again at cylinder 9, head 9.

the

After all tracks have been written, stop the FTU.
Writing will begin again at cylinder 9, so the actual
stopping point is not important.

2.5.5.4
Read - This operation tests the entire data
errors, using the sequential reverse access mode.
1.

pack

Set the switches as shown below.
All others
remain as given f~r the write-format procedure.
Swi tch

Posi tion

DISPLAY SELECT

CYLINDER

ADDRESS MODE

SEQ REV

WRT-RD SELECT

for

should

Set the CYLINDER ADDRESS swi tches to the maximum cylinder
address (14668).

Actuate START.
Reading will begin at maximum cylinder,
head 9. Should an error occur, the RUN light will go out
and the panel lamps will display the type of error as
well as the cylinder that was being read when the error
occurred •. Follow steps 4 and 5 for each separate error
stop.
If no errors, skip to step 6.

Record the error
switch as needed.

parameters,

moving

the

DISPLAY

SELECT

NOTE
It is not necessary to record the ERROR
COUNT. This will remain at count 1 for
any stop-an-error operation.
5.

After the error parameters have been recorded, actuate
RESET to clear the error indication in the FTU.
Then
actuate START to continue reading.

When the FTU begins reading again at the maximum cylinder
address, actuate STOP to halt the FTU • .

2-72

2.5.5.5
Write Flag - A single read may produce random errors
that a host system error-recovery program would eliminate in an
on-line environment. Before flagging a track as bad, i.e, as one
that continually produces errors that are not recoverable, it is
best to WRT-RD the track several times.
If the error per si sts,
execute the trouble analysis procedure below in an effort to
recover the error.
Flag the track onl y after both of these
procedures have failed· to correct the problem.
The procedure given below writes a -defective track" flag in bit 6
of address word 1 (Figure 2-32).
ADDRESS
F~ELD

ZEROS

DATA~~~EL_D

ZEROS

______

f
HOME ADDRESS
PROTECT GAP

~~~
,
INDEX

GAP

I DATA WORD 2 ,

HEAD
ADDRESS

'----CY-L-tN.,.D-E-R---.·A~~
.. I-N-D...
ICA-T-ES-"
ADDRESS

WRITE FLAG BIT
ADDRESS SYNC BIT

Figure 2-32

UNUSED BIT
DATA SYNC BIT

I·BIT DATA PATTERN
IS REPEATED FOR THE
.ENTIRE DATA FIELD.
EXCEPT THAT BIT 7 OF
WORD 1 IS A SYNC BIT

Track Format
NOTE

The format In i'igure, 2-32 Is a special
format used by the PTU. The pack'should
, be
reformatted
before
any
last
diagnostics are run.

2-73

Set the FTU swi tches as shown below. The other switches
should remain as in the preliminary setup procedure.
Swi tch

Position

WRT FUG

Up (ON)

DISPLAY SELECT

READ DATA

ACCESS MODE

DIRECT

WRT-RD SELECT

WRT FORMAT

DATA PATTERN

As set when the track was
most recently written

CYLINDER ADDRESS

To select the track

HEAD ADDRESS

To be flagged

SEQ-MAN

MAN
The drive will seek to the

Actua te RESET, then START.
selected track.

When the ON CYL light comes on, wait about one second and
then actuate STOP.

Set the the WRT-RD SELECT switch to RD.

Actuate START.
The "defective track" flag will prohibit
read ing the track.
The ADDRESS ERROR and DATA ERROR
indicators should not light up.

Actuate STOP.

Repeat steps 1 through 6 for each track to be flagged as
tivell

dp-f~c

NOTB
The WRT fLAG swi tch lDust be turned off
before reading a track that ha. not been
written aD defective. An address error
will occur If it Is not turned off.
2. s. 5. 6 Cheek Data-Error Log ie - This proced ure assures the
operator that the rTU will recognize data errors. Use it whenever
you expect data errors but none occur.
It assumes the procedure
in question is still running and the scratch pack, therefore, has
a data field written on the tracks being tested.
1.

STOP the rTU.

3-74

Set the PTU switches as shown below.
(Note their
position as you will return them at the end of this
pr oced ure • )
Switch

Position

WRT-RD SELECT

DATA ERROR BYPASS

Down

DATA PATTERN

Choose anyone swi tch and
move it to the opposite
position. Move just one.

(OFF)

All other switches must remain as they were at the start
of the procedure being questioned.
3.

START the FTU.
indicator lit.

The FTU should stop wi th the DATA ERROR

Actuate RESET to clear the error indication.

Set the DATA ERROR BYPASS switch up (ON).

Actuate' START. The FTU should r'un wi thout stoppi ng on an
error, but the RD/WRT ERROR counter will count the errors
(up to 15).

. STOP the FTU.
Return . all switches .. used during this
proced ure to the state they were in at the start of the
procedure being queationed.

2.5.5.7
Trouble Analysis - Table 2-3 is a decision log ic table
(DLT) • It shows the procedures the operator should take to el iminate any error that might occur when using the FTU to exercise a
drive. Address and data errors will, of course, occur only during
one of the read or write modes. Other errors may occur for either
read/write or access-only modes. Note that sector mark and sector
count errors are not indicated if the ADDRESS ERROR BYPASS switch
is active.
Basically, .the D1-T. indicates the procedures to follow to either
eliminate or recover data and address errors before writing a
-defective track- flag on the track in error.
These procedures
involve trying various OFFSET and DATA STROBE switch combinations.
The DLT has four quadrants. The DLT reduces each test condition,
shown in the upper-left quadrant, to a yes (Y) or no (N) shown in
the numbered columns of the upper-right quadrant.
There are two
columns for each test condition. The two lower quadrants provide
recommended actions.

2.-75

To determine what actions, if any, to execute for a given test
result, follow the selected column down to the number "1" (the
first recommended action) in the lower-right quadrant. Locate the
speci fic action to take by following across to the lower-left
(actions) quadrant. After you have accomplished action 1, repeat
the test that gave rise to the error condition.
If the error
persists, perform action 2, test again, and so on. An "X" in the
lower-right quadrant indicates a "no error" or a "problem solved"
situation which requires no further remedial action.
Columns 12 through 20 define the sequential tests that were alluded to in the second paragraph of this procedure. Use these actions to attempt to recover data errors.
Note that the last action item in any of these "yes" (even-numbered) columns instructs
the operator to set up the next condition or test for rereading
the track In error. Only when the last of these sequential 'tests
has failed to recover the data should you carry out the write flag
procedure indicated in action 3, of column 20.
2.5.6 Preparation of the Drive for Return On-line after Testing
The procedures below prepare the drive for return to normal
on-line operation after completing tests with either FTU or
software.
1.

Press the START switch to stop the drive motor and unload
heads.

Open the pack access cover and remove the scratch or CE
disk pack.

Close the pack access cover.

Open the rear cabinet door and set the MAIN AC circuit
breaker to OFF.
NOTE
If the test software was used, proceed
to step 9. If the FTU with standard I/O
connection was used, proceed to step 5.

Disconnect the FTU standard I/O cables from J2 and J3 on
the drive I/O panel.

Reconnect the system I/O cables to drive In the same
conf ig urat ion as they were pr ior to installat ion of the
FTU, then replace the I/O panel cover.

If any card was installed on the card extender, remove
the card extender and replace the card in the log ic
chassis.

2-76

If the head alignment was perfor.ed, remove the head
alignment card from location A16. Also, remove the head
alignment cable which is connected from E83 on the
read/write chassis to A16 on ·the drive backpanel.

Replace the cover on the card cage and secure wi th the
turnlock fast-ener.

le.

Close the logic chassis and rear door.

11.

Close the cabinet top cover, if it has been open.

2.6

FIELD ACCEPTANCE PROCEDURE

2.6.1

Introduction

The field accept.ance testing demonstrates the performance of the
RMeS Disk Dr ive to the customer pr ior to his acceptance of it.
2.6.2
Error De:fini tions and Rates
The drive contains two registers to display the error conditions
possible.
Error registers 1 and 2 (RMERI, RMER2) indicate the
drive error conditions.
One bit of RMER2 (SKI) indicates seek
errors and is used .to calculate the seek error rate·· (parag raph
2.6.2.4) • Four bi ts of RMERl (HeRC, HCE, ECH, and DCK, which may
include DTE and .FER) indicate data errors. The remaining bits ef
RMERI indicate command and control errors.
Table 2-4 lists
. indications of the various error :typesand their~· explanations.

Table 2-4

Error Conditions
Error

Bit

Type

Explanation

HeE
HeRe

RMERI
RMERI

Soft

The header field does not compare with
the desired address. The sector compare
fails due to the eRC failure.

HCRe

RMERI

Soft

The header field matches the desired
address but there is a CRC error.

HeRe
FER

RMERI
RMERI

Soft

The format
incorrect.

bit

in the first header is
NOTE

An PER without HCRC during an operation

that reads the beader Ind icates
wrong format pack mounted.
Del(

RMERI

Soft

the

An error is detected during the read
operation by an examination of the ECC
bytes; it is correctable by retry
sequence.

2-77

Table 2-4

Error Conditions (Cont)

Bit

Error
Type

DCK
ECH

RMERI
RMERI

Hard

SKI

RMER2

Seek

Explanation
An error is detected which is
ECC-uncorrectable through 28 retry
sequences (16 retries at nominal
position and 12 with head offset).

head

1.
A seek operation fails to complete
within 500 milliseconds of initiation.
2.
A recalibration operation fails to
com p 1e te wit hi n 500 mill i s 9 co nd s 0 f
initiation.
3.
An offset or return-to-center1 ine
operation fails to complete within 10
milliseconds.

SKI

RMER2

Seek

Tbe positioner has drifted off the
cylinder subsequent to completion of the
positioning operation.

HCE

RMERI

Seek

~he

header field does not match the desi red address, and there is not a CRC
error.
This error may be caused by a
pos i t ioner fa i lure or an RM ada pte r
failure

2.6.2.1
Hard Errors - Any failure to read data c~rrectly after a
complete recovery sequence wi th ECC enabled consti tutes an irrecoverable, or hard, error. A complete recovery sequence consists
of twenty retries, sixteen at the nominal head position and two at
each offset position.
Errors that are not ECC-correctable include bursts greater than 11
bits in length and isolated dropped bits separated by more than 11
bits within one sector. The allowable error rate for hard errors
is one error per 1012 bits read.
2.6.2.2
Soft Errors - Any failure to read data correctly on the
first try that is then successfully read dur ing a recovery 'sequence consti tutes a recoverable or soft error.
(Refer to paragraph 2.5.2.1 for the definition of a complete recovery sequence.)
The allowable error rate for soft errors is one error per 1010
bits read.

2-78

2.6.2.3
Pack-Attributable Brrors - An error caused by imperfections in the record ing surface 1s a pack-attr ibutable error.
If
the imperfection is less than 11 bits long, it is seC-correctable
and will appear as a soft error. If it Is more than 11 bits long,
it will appear liS a hard error.
On a given pack, pack-attributable errors will always appear at the same cylinder, sector and
track addresses, with- an sec P~S REG value within 11 bits.
The
defini tions of hard and soft errors in paragraphs 2.6.2.1 and
2.6.2.2 apply only to randomly distributed errors, and do not take
into· account errors that are pack-attributable.
Imperfections in
the pack surface may be found by mapping the pack usi~g the formatter program, but there is no guarantee that they will all be
found.
2.6.2.4
Seek Errors - A seek error is any positioning operation
that is not completed within 50" milliseconds for seek commands,
500 milliseconds for recalibrate commands, and 10 milliseconds for
offset and return-to-centerline commands, or that terminates with
the positioner in an incorrect location. The allowable error rate
for seek errors is one error per 106 seek operations.
2.6.3
Pield Acceptance Test Diagnostic Programs
These diagnostic programs may. be used individually or in
combination ·to demonstrate the performance of the disk drive. Use
the following diagnostic programs for the RM05 Disk Drive.
Refer
to the applicable diagnostic operation procedures for more
detailed information.
Test Programs

MAINDEC-ZZ-CZRMV

Extended drive test

MAINDEC-ZZ-CZRMR

Dual-port logic test, part 1

MAINDEC-Z Z-CZRMS

Dual-port logic test, part 2

MAINDEC-ZZ-CZRMP

RM05 .diskless controller
part 1

test,

MAINDEC-ZZ-CZRMQ

RM05 diskless controller
part 2

test,

MAINDEC-ZZ-CZRMM

RM 0 5
fun c t ion a 1
test, part 1

controller

MAINDEC-ZZ-CZRMN

RM05
functional
test, part 2

controller

MAINDEC-ZZ-CZRMO

RM05
functional
controller
test, part 3.
Format the pac K
before doing part 3

,·-79

System Exerciser Progra.s
MAINDEC-ZZ-CZRMU

Performance exerciser,
formatted pack

MAINDEC-ZZ-CXRMC

DEC/Xll system exerciser

need

Utility Programs
MAINDEC-ZZ-CZRML

Formatter program, need good
pack

MAINDEC-ZZ-CZRMT

Drive compatibility test

2-80

CHAPTER 3

MAINTENANCE

3.1
GENERAL MAINTENANCE
This chapter contains preventive and corrective maintenance
information for the drive.
The maintenance described here Is
directed toward field representatives. The information is divided
into the areas described below.
•

General Maintenance Information - Contains general
information that a Field Service Engineer should be
familiar with prior to performing maintenance on the
drive.

•

Preventive Maintenance Information - Gives the preventive
maintenance schedule for the procedures that must be
performed to maintain proper drive operation.
(Refer to
the RM05 Preventive·MaintenanceManual for detailed
informafion. )

•

Tests and Adjustments - Contains procedures describing
the electr ical adj ustments that may be per formed on the
drive in the field.

•

Trouble Analysis - Describes tests that may be performed
to isolate problems with the drive.
(Refer to the RM05
Fault Isolation Guide for detailed information.)
----

This chapter also contains general information relating to
ma intenance of the dr i ve. A person per forming maintenance on the
drive should be familiar with this information in addition to the
operating principles and procedures described in the RM05
Technical Oeser if)tion manual.
---

NOTE
Be sure to include the hour .eter
reading on the authorized test section
of t,he LARS form.

3-1

The information
descr i bed below.

the

following

divided

into

the

areas

•

Safety Precautions - Lists safety precautions that must
be observed when working on the drive.

•

Maintenance Tools and Materials - Lists the' tools and
materials required to perform maintenance on the drive.
This includes descriptions of the types of disk packs
used during maintenance procedures and
the head
alignment kit card.
Drive tests and adjustments
requiring test software or the field test unit (FTU) are
also described.

•

Accessing Dr ive for Maintenance - Descr ibes the features
of the drive which allow access to its subassemblies.

•

Maintenance Controls and Test Points - Describes location
of test points (both cards and backpanel) referred to in
maintenance procedures.

•

Manually Positioning the Carriage - Describes
heads may be loaded and positioned manually.

•

Special Maintenance Procedures
procedures and practices that are
maintenance of the drive.

•

YOE Versus HON-VDE Differences - The RM05 has VDE and
NON-VDE versions.
The VOE versus NON-VOE differences
will be called out in this manual where appl icable.
VDE
differences include:

how

the

Describes certain
impor tant to proper

•

Redesigned power supply

•

Motor relay box between power supply and drive motor

•

Motor assembly with direct drive brake

•

Improved design pack access cover interlock

•

Hinge on logic chassis.

3.2
SAFETY PRECAUTIONS
Observe the following safety precautions at all times. Failure to
do so may cause equipment damage and/or personal injury.

•

Use care while working with the power supply.
voltages are present inside the ac power assembly.

3-2

Line

•

Keep halrlds away from the actuator dur ing seek operations
and when reconnecting leads to the voice coil.
Under
certain conditions, emergency retract voltage may be
present, causing Budden reverse motion and head
unloading.

•

Use caution -while working near the head assemblies.
Fingerprints may damage the heads or the disks.

•

Keep pack access cover closed unless it must be opened
for maintenance. This keeps dust out of the pack area.

•

Keep all watches, disk packs, meters and other test
equipment at least two feet away from the voice coil
magnet when the deck cover is off.

•

Do not use the CE alignment disk pack unless specifically
instructed to do so.
These packs contain prerecorded
alignment data that can be destroyed if test procedures
require the drive .to. perform a. write operation.
This
a1 ignment data cannot be recreated in the field.

•

If the drive fails to power down when the START switch is
depressed, disconne.ct the yellow leadwire to the voice
coil and manually retract· the heads :before trouble-'
shooting the malfunction.

•

Make certain that the heads are unloaded before turning
off poweJr.

•

If power to the drive motor is lost while heads are
loaded and the voice coil leadwire is disconnected,
immediately retract the carriage.
Otherwise, the heads
will crash when the disk speed is too low for the heads
to fl y.

•

The -YFN card in the NON-VDE power supply requires
special· handling. Observe the safety precautions
described in the discussion on Handling Electrostatic
Devices.

not use
shooting.

the

customer's

disk

pack

d ur Ing

troubl e-

3.3
MAINTENANCE 700LS AND MATERIALS
Table 3-1 lists special tools, test equipment and materials
required to perform preventive and corrective maintenance on the
dr ive.. The CONTRC)L DATA and DIGITAL part number for each of these
items is also listed.
Most of these items require no special
instructions for their use. Special instructions, when necessary,
are included in the maintenance procedures.
The disk pack, the
head alignment kit and the FTU all require special instructions.

3-3

Table 3-1

Maintenance Tools and Materials

DIGITAL PIN

CDC PIN

Description

29-13212-90
29-29996-90
29-22933-90
29-22934-90
29-22935-90
29-22936-00
NA
NA
NA
NA
NA

12218425
12263205
54109701
75018400
75018803
87016701
NA
NA
NA
NA
NA

Torque screwdriver 2~35 in-lbs
Torque wrench
Card extender
Carriage spindle alignment tool
Head adjustment tool
Screwdriver bit
Tool kit
Hex wrenches, metric
O'scope
DVM
Cleaning pads and cloths

3.4
DISK PACK
The maintenance procedures refer to three types of disk packs: (1)
customer, (2) scratch, and (3) CE.
All three are physically
identical but are used for different purposes.
"Customer pack" refers to an RM05-P disk pack used for data
storage during the customer's normal on-line operations.
A "scratch pack" Is simply an RM05-P disk pack that does not
contain any customer or other information that must not be
destroyed.
Therefore, a scratch pack can be used in maintenance
procedures where the possibility exists that a pack could be
damaged or its' information altered or destroyed.
The "eE pack" contains special prerecorded information used during
maintenance.
Make sure that this data is not destroyed or
altered. A CE pack cannot be reconstructed in the "field.
3.4.1
Disk pack Handling
The RM05-P cannot be cleaned. If improper operating conditions of
the pack exist, the following symptoms may be observed and the
pack should be removed immediately.
•

A sudden increase in error rates related to one or more
heads is observed.

•

An unusual noise such as pinging or scratching is heard.

•

A burning odor is smelled.

•

Contamination of the pack from
similar substances is suspected.

3-4

dust,

smoke,

oil,

If there is any doubt about the pack's functional condition, have
it inspected.
Enclose a descr iption of the known or suspected
malfunction.

CAUTION
Do net atteapt to operate a pack that Is

suspected
of
being
contaminated.
Inspect drive beads and shroud area for
contamination and/or damage.
Do the
above .entioned prior to operating the
drive with another pack.
3.4.2
Disk Pack Inspection
In some cases, it may be possible to inspect the disk pack. This
task must be performed by properly trained personnel only and is
recommended every 6 months.

NOTE
Inspection of disk packs in the field
can cause additional problems for the
following reasons:
•

Exposure of the pack to non-clean
room conditions during inspection
may additionally contaminate the
pack.

•

. Disk. surfaces aay be . scratcbed by
using contaminated or
i.proper
inspection equipment.

•

The pack .ay be daaaged while the
covers are removed.

3.5
HEAD ALIGNMENT KIT
The head alignment card develops an output voltage which is
derived from the output of the servo and read/write preamplifiers.
When a CE disk pack is installed on the drive, this output voltage
will be proportional to the distance a selected head is offset
from the track centerline.
The head alignment card plugs into
card location A16 In the RM05 logic chassis.
The head alignment card incl uded in the ki t 1s ei ther the -FSV
card or the -ZPV c::ard.
The only difference between the cards is
that the -ZPV card does not have the four indicators found on the
-FSV card (Figure 3-1).
The following togC3)le switches control the operation of the cards
(Figure 3-1).
S1

Changes the polar i ty of the al ignment signal and is used
In aligning both servo and read/write heads.
This is
done by following the steps listed below.

3-5

o POW.EB
INDICATORS

{

SEE NOTE 3
S1

:(
I
II
1

OINPttT
0 BAD TRK
o MODE
p
N COMPONENT
S SIDE OF
RW CARD

_FSVCARD

SEE NOTE 2

17 .....

34 .....

SEE NOTE 1

.1.v ~+

NULL METER
50-500

HEAD ALIGNMENT
CABLE
CONNECTS TO PINS
8 THROUGH 11, A AND B

LOGIC CHASSIS
WIRE WRAP PINS

5_0~~50

HEAD SELECT/
READ AMPLIFIER
CARD
E03

NOTES
1.
. 2.
3.

METER IS PART OF FTU OR HEAD ALIGNMENT KIT.
METER READINGS TO LEFT OF ZERO ARE NEGATIVE
AND READINGS TO RIGHT OF ZERO ARE POSITIVE.
NEWER KITS HAVE _ ZPV.
INDICATORS 00 NOT APPEAR ON _ ZPV CARD.
CZ·0284

Figure 3-1

Head Alignment Kit

Note null meter reading when switch is in P position.

Note null meter reading when switch in in N position.

Subtract N reading from P reading to determine the
alignment error. For example:
If P -

+39 mv and N -

(-40) :. +79 mv.

-49 mv,

then P - N ::a (+39) -

When the swi tch is in the S posi tion the card selects the
servo head as an input.
When the swi tch is in the R/W
position, it selects a data head input to the card.

Changes the sensitivity of the card.
When in X.l
position, the sensitivity is reduced by a factor of 19.
When in the Xl position, the sensitivity is not reduced.
This swi tch should be in the Xl posi tion when making
measurements for use in calculating head alignment error.

3-6

Four ind icators are provided on the -FSV card as moni tor s to
ensure the card Is operating properly and Is receiving the proper
data. These ind i,cators are:
Power

When lit,
card.

Input

When lit, it indicates that the input signals are too
low fc)r the alignment card circuits to operate.

Bftd

When lit, it indicates a short duration loss of input.
A one shot ma i,nta ins the li t cond i t ion for at
least four seconds.
This indicator lights when the
Slswitch is operated.

Track

Mode

indicates that power

is applied

the

When lit, it indicates that either S2 is in the servo
position or 53 is in the X.l position. When either of
the sec 0 n d i t ion sex i s t, R/ W he a d ali 9 n men t err 0 r s
cannot be measured.

The card receives its input via the head alignment cable which is
a part of the head al ignment kit.
This cable connects between
A16, pins 8 through.ll,. and Jl on the read amplifier board in R/W
chassis location E03.
The output vol tage of the card is measured by a null meter which
connects via test leads to test points X ~nd Z on the card (Figure
3-1). This meter is either part o'f the 'FTU or is a separate unit
if the head alignment kit is being used.
The switch on the front panel of the meter changes the sensitivity
of the meter.
When the swi tch is in the 50 posi tion, the meter
reads to +50 millivolts. When the switch is in the 500 position,
the meter-reads to +500 millivolts. This switch should be in the
:t50 millivolts posltion when making measurements for use in
calculating head alignment errors.
3.6
TESTING DRIVE WITH FTU OR SOPTWARE
The FTU and test software prov ide var ious functions necessar y to
perform most of the electrical tests and adjustments described in
this manual. The following paragraphs describe the general use of
both the FTUand software for testing the drive.
3.6.1
Testing with the PTU
The FTU is an off-line tester.
This means that the dr ive cannCJt
be selected or used by the controller while tests are per formed
wi th the FTU.

The FTU connects to the dr ive by way of standard I/O cables. Th is
requi res that th.~ system I/O cables be disconnected and the FTU
cables connected in their place. Refer to Appendix A of the RM05
Disk Subsystem Service Manual for detailed information concernrng
the operation, installation and use of the FTU.
3-7

3.6.2
Testing with Software
The drive can also be tested by use of software test routines.
This requi res use of the controller and the appropr iate software
or diagnostic operating systems.
In this type of testing, the
drive communicates with the controller during normal operations.
Special I/O connections are not required.
I/O connections, except for the proced ure for prepsr ing the dr ive,
are the same as when using the FTU.
These connections are
described in paragraph 3.6.3.
Refer to other documentation, such as the RM~S User Guide,
applicable to the specific system or subsystem for informatlon
concerning the test software routines.
3.6.3
Preparation of Drive for Testing
This section describes the procedure that prepares the drive for
testing with either the FTU or software.
1.

Press START to stop the drive and unload the heads.
NOTE
All procedures other than head alignment
require installation of a scratch pack.
Head alignment requires installation of
a CE pack.

Raise the pack access cover, remove the customer disk
pack, and replace it with a scratch pack.

Close the pack access cover.

Set MAIN AC circuit breaker on the rear door to OFF.

Release the logic chassis latch and swing chassis open.

Connect the FTU standard
follows (Figure 3-2):

I/O

cables

the

drive

Turn the I/O panel fastener counterclockwise and
remove the panel from the upright support. This will
allow the panel to be posi tioned so the cables can
easily be installed.

Remove the hardware secur ing the I/O panel cover to
the I/O panel.
Remove the cover and set it as ide.
The cover is not replaced until maintenance is
completed.
NOTE
Steps c through e refer to either a
channel 1 or 2 connection, whichever is
used.
3-8

REAR DOOR

F T U - - -.......

CZ·0&3S

Figure 3-2

Standard I/O Connection

Disconnect the I/O cables from J2 and J3 on the drive
I/O panel.

Install tester A cable to J3 and B cables to J2.

Position the I/O panel on the upright support and
secure it with the I/O panel fastener.

If the dr ive is in a system that is daisy-chained,
make necessary connections to ensure that other
drives remain under system control.

Loosen the turn-lock fastener securing the card
cover to the logic chassis and remove the cover.
3-9

cage

Install the card extender if the test or adjustment
procedure being performed requires it.
This is noted in
the procedure.
.

If head alignment is being performed, proceed as follows:
a.

Install
A16.

the head alignment card

(HFSV)

in location

Connect the head alignment cable from logic backpanel
location A16, pins 8 through 11, to Jl on card E03 in
the R/W chassis.
Refer to head alignment procedure
for detailed information.

10.

Set MAIN AC circuit breaker to ON.

11.

Press the START switch to start the drive motor and load
the heads.

12.

Select drive.
When the drive is selected,
for tests and/or adjustments.

it is ready

3.6.4
Preparation of Drive for Return On-line After Testing
The following prepares the drive for return to on-line operation
after completing tests witn either FTU or software.
1.

Press the START switch to stop the drive motor and unload
the heads.

Raise the pack access cover and remove the disk pack.

Close pack access cover.

Open the rear door and set the MAIN AC circuit breaker to
OFF.

Disconnect the FTU standard I/O cables from J2 and J3 on
the drive I/O panel.

Disconnect the terminator, if used, from J4 on the drive
I/O panel.
The terminator is not required for normal
on-line operation.

Reconnect the system I/O cables to the dr ive in the same
configuration as they were prior to the installation of
the FTU and replace the I/O panel cover.

If any card was installed on the card extender, remove
the card extender and replace the card in the log ic
chassis.

3-10

If a head alignment was performed, remove the head
alignment card from location A16. Also, remove the head
alignment cable which is connected from Ee3 on the R/W
chassis to A16 on the back of the drive.

10.

Replace the cover on the card cage and secure it with the
turnlock fast~ner.

3.7
ACCESSING THE DRIVE POR MAINTENANCE
The doors and covers on the RHOS provide access to its major
assemblies. Figure 3-3 shows all of the covers and doors and they
are further described in the paragraphs below~

LOGIC
CHASSIS
POWER
SUPPLY
SHROUD

CZo0382

Figure 3-3

Accessing the Drive for Maintenance
3-11

3.7.1
Cabinet Doors
T-he dr ive has doors on both the front and rear of the cabinet.
The front door provides access to the blower assembly.
Immediately behind the front door is a safety shield.
If the
safety shield and blower assembly are removed, the lower part of
the spindle and its associated parts may also be accessed.
The
rear door allows access to the log ie chassis, power supply, and
drive motor.
The front door is opened by pushing the latch and
swing ing the door outward as shown in Fig ure 3-3.
Open the rear
door by releasing the latch wi th a 6mm hex and swing ing the door
outward.
The doors are removed by first removing the ground
strap, then lifting out the pin secur ing the door to the lower
hinge and slipping the door off the upper hinge.
The doors are
replaced by reversing the removal procedure.
3.7.2
Cabinet Top Cover
The top cover must be raised to access the deck assembl ies.
It
must be removed pr ior to removing the shroud cover, shroud, pack
access cover, or deck cover.
The top cover has no latch and is raised by lifting it from the
rear until the support locks into place (Figure 3-4).
The
following section describes removal and replacement of the top
cover.
Note that if the drive is installed in line with other
drives it must be rem'oved from the in-line position before the
cover can be removed or replaced.
. 3.7.2.1

Top Cover Removal

Raise the top cover until the support
upright position. Remove ground strap.

Remove nuts from screws holding each side of the top
cover but do not remove the screws.
The cover should
remain in the raised position supported by the screws and
the support brackets.

Remove the C-clip securing the support bracket to the top
cover, then lower the support bracket and the top cover
to the closed position.

Remove the screws from the top cover hinges and lift the
top cover off the drive.

3.7.2.2

locks

Top Cover Replacement

Set the top cover on the drive.

Insert screws through the hinges and the drive frame.
NOTE
The cover should be supported by
screws when it is raised 1n step 3.
3-12

the

SUPPORT ROD

HINGE

9W7

Figure 3-4

Top and Deck Covers

3-13

Lift the top cover to the raised position and secure the
support bracket to the top cover with C-clip.
Reinstall
9 ro und strap.

Install
frame.

nuts on the screws secur ing

the

hinges

the

3.7.3
Deck Cover
The deck cover (Figure 3-4) must be removed to access the rear
half of the deck.
This includes the actuator and the magnet
assemblies.
This cover provides an electromagnetic interference
shield for the drive. The cover is lined with acoustical foam to
reduce machine noise.
The cover is removed by releasing the latches and lifting i.t off
the deck.
3.7.4
Logic Chassis
The logic chassis is located at the rear of the drive and is
accessed by opening the rear door.
Releasing the ca tch on the
logic chassis allows it to swing outward, thus permitting access
to the card cage (Fig ure 3-5).
The card cage cover must be
removed in order to reach the logic cards. Use care not to damage
the cables or air hose when opening and closing the logic chassis.
3.7.5
Pack Access Cover
Raising the pack access covers allows access to the disk pack and
shroud area of the drive. Once opened, the cover is held in place
by a gas spring (refer to Figure 3-6).
A solenoid, located on the
front of the shroud cover, prevents accidental opening of the pack
access cover while the drive is in use or when the drive is
completely powered down.
In fact, the only time when the cover
can be opened without overriding the solenoid is when the MAIN AC
circuit breaker is ON, but the START switch is OFF.
The deck cover (refer to Figure 3-4) must be removed to access the
rear half of the deck.
This includes the actuator and magnet
assemblies.
The purpose of this cover is to provide an
electromagnetic interference shield for the drive.
The cover is
lined with acoustical foam to reduce machine noise. The cover is
removed by releasing the latches and lifting it off the deck.
The pack access cover solenoid can be manually actuated on NON-VD!
units.
Pull down on the solenoid latch while pulling up on the
pack access cover latch release. On VDE uni ts, the dr ive must be
in the standby mode (power on, motor stopped) to open the cover.
The pack access cover will remain locked for approximately 30
seconds after the MAIN AC circuit is turned on.
The pack access cover is removed and replaced as described in the
following procedures.

3-14

LOGIC CHASSIS
RELEASE LATCH

LOGIC CHASSIS

twe
Figure 3-5
3.7.5.1

Logic Chassis

Pack Access Cover Removal

Remove the cabinet top cover.

Remove the C-cl ip sec ur ing
access cover.

Disconnect the ground lead from the pack access cover.

Remove the screws and nuts securing the pack access cover
hinges to the shroud cover and remove the pack access
cover.

3-15

the gas spr ing to the pac k

3.7.5.2

Pack Access Cover Replacement

Install the pack access cover on the shroud cover by
securing the hinges with nuts and screws.
Before
tightening the screws, ensure that the cover is cen tered
on the shroud.
Also ensure that the clearance on the
front of the shroud is such that the pack access cover
solenoid will properly engage.

Secure the gas spring to the pack access cover using pin,
nylon spacers, and C-clip (Figure 3-6).

Connect the ground lead to the pack access cover.

Ensure that a tight air seal exists between the pack
access cover and the shroud cover.
This can be checked
visually and also by noting the drag on a sheet of paper
as it is pulled out from between the closed pack access
cover and . the shroud cover.
Adjust, if necessary, by
moving the catch on the shroud cover up or down until the
pack access cover latches tightly enough to provide an
air seal.

3.8
POWER SUPPLY
The power supply is located on the floor, at the rear of the
cabinet.
Two types of power supplies are used.
These are
illustrated in Figure 3-7A.
As illustrated, one power supply is
. mounted on slides that permits extending it out the rear of the
cabinet.
The other- power supply is mounted on the base of the
cabinet and does not incorporate the slides. Both power supplies
contain replaceable cards.
3.8.1

NON-VDE Power Supply Access

Swing the logic chassis outward far enough so that the
chassis is not damaged when the power supply is pulled
out.

Lift the power supply release latch and pull
supply out to the maintenance position.

the power

The top cover can be removed when the power suppl y is in the
maintenance position. Remove the screws at the rear of the cover
and then loosen the front screws. Slip off the cover.
The power supply control panel is hinged on its bottom edge to
allow access to components on the back of the panel. To open the
control panel, first remove the top cover, then remove the screws
on each side of the panel and pull it open.

3-16

3.8.2
VD! Power Supply Access
The power supply shown in Figure 3-7, Is mounted directly to the
cabinet base.
A lip at the back edge of the power supply slides
under a bracket secured to the cabinet base.
Two 118-24 x 3/8
self tapping screws and external tooth lockwashers aecure the
front edge of the power supply to the cabinet base.

...~

j~~

".~
~~

~
I

-A-

LATCH
RELEASE

.------

PACK
ACCESS
-COVER

GAS
SPRING

HINGE

CATCH
PACK ACCESS'&
COVER INTERLOCK
SWITCH

PACK ACCESS
COVER SOLENOID

.& PART OF INTERLOCK ASSEMBLY ON VDE UNITS
~ INTERLOCK ASSEMBLY ON VDE UNITS
Figure 3-6

lOJ3

Pack Access Cover

3-17

"P" CLAMP

SUPPORT SPRING

I NON-VDE I

CABLE GUIDE
Figure 3-7

Power Supply Assembly

3-18

lOJ13

Removal of the two 119-24 mounting screws permits the power supply
to be pulled rearward within the limits of the free length of the
,cables and blower hose.
Servicing of the power supply will
generally require 'its removal from the cabinet. The cover can be
removed. The power supply can then ,be repositioned in the cabinet
for power on tests.
3.8.3
Motor Relay Box Assembly
The motor relay box assembly Figure 3-7 is installed in VDE units
only. It is· mounted on the frame between the power supply and the
air supply. The relay box contains the AWNV relay board. There
are two trailing cables from the box for connections to the power
supply and the drive motor.
The relay box controls motor start
and mo tor run cur rent.
To access the relay box, r a i se the to p
cover of drive. Release the latches for the right side panel and
remove.
Disconnect the ground strap between the side panel and
dr ive frame.
3.9
SIDE PANELS
The dr i ve has both left and r i9 ht side panel s.
The panel s are
removed by pulling up on the release latches, swinging the panels
outward far enough to disconnect the ground straps, and then
removing the panels. from ,the drive (Figure 3-8). The panels are
replaced by reversing the removal procedure.

3.1S
SHROUD A'ND SHROUD COVER
The shroud and shroud cover enclose the pack area and the front
portion of the {deck (see 'Figure 3-9).
They must be removed to
Their removal and
perform certain maintenance procedures.
replacement is described in the paragraphs below.
3.1S.l

Shroud and Shroud Cover Removal

Remove the cabinet top cover.

Remove the pack access cover.

Remove the screws holding the pack access cover switch to
the shroud cover. Let the switch hang by the leadwires.
NOTE
On VDE units, the pack access cover
solenoid and pack access switch are
integrated into one interlock assembly.
Remove
the
interlock assembly by
removing the two screws attaching it to
the front of the shroud cover. Let the
assembly hang by the leadwires.

Snap the operator control panel out of its position in
the shroud cover, disconnect the control panel cable
plug, then snap the control panel into place.
3-19

SIDE PANEL
RELEASE LATCHES

STRAP
SIDE PANEL
SUPPORT BRACKET
SIDE PANEL
9WIO

Figure 3-8

Side Panel

Move the shroud cover far enough forward to disconnect
the solenoid leadwires. Disconnect A3P9 connector on VDE
units.

Remove the screws holding the shroud cover to the shroud.
Take off the shroud cover.

Take off the hardware securing the parking brake cover to
the shroud cover and remove the parking brake cover.

Take off the hardware securing the shroud to the deck and
remove the shroud.

3-29

PARKING BRAKE
COVER

PACK ACCESS
COVER SOLENOID

& PART OF INTERLOCK ASSEMBL Y ON VOE UNITS
Lt INTERLOCK ASSEMBLY ON VOE UNITS
~ VDE UNITS ONLY
Figure 3-9
3.10.2

SHROUD
COVER
lOJ5

Shroud and Shroud Cover

Shroud and Shroud Cover Replacement

Position the shroud on the deck and secure it.

Reconnect the solenoid leadwires and connector A3P9 on
VOE units before securing the shroud cover to the shroud.

Reattach interlock assembly to shroud cover on VOE units.

Position the shroud cover on the shroud and secure it.

Secure the parking brake cover to the shroud.

Snap the operator control panel out of its position in
the shroud cover, connect the control panel cable plug to
the operator control panel, and snap the control panel
into its position in the shroud cover.

Posi tion the pack access cover swi tch under
cover and secure it.

Replace the pack access cover.

Replace the top cover.
3-21

the shroud

Table'3-2

Maintenance Controls and Indicators

'Control or Indicator

Function

Maintenance fault
clear switch

Clear position clears the fault
latch and five fault status latches.
When the switch is actuated, the
fault indicators on the edge of the
fault.card go off and remain off unless a cond i tion causing . the faul t
rema ins.
NORM is the normal operating position for the switch and the position
to which it returns when released.

Voltage fault indicator

Lights to indicate
voltage exists.

below-normal

Write fault indicator

Lights to indicate
fault exists.

that

Multiple head select
Fault indicator

Lights to indicate a
select is occurring.

multiple h~ad

Write and read fault
indicator

Lights to indicate that both a write
and read are commanded simultaneously.

Write or read and off
cylinder indicator

Lights to indicate that a write or
read is selected dur ing a seek operation (not on ~ylinder).

write

The operator panf~l and the power suppl y .control panel swi tches and
indicators are detailed in the RM05 User Guide and the RM05
Technical Description manuals.
3.11.2 Test Points
When performing the electrical checks and adjustments described in
this text, it is necessary to monitor signals at various points in
the drive logic Qr other circuitry. There are three categories of
test points:
(1) pins of the logic chassis wirewrap panel, (2)
test points located on a card in the logic or R/W chassis, and (3)
test points on the power supply control panel.
3.12
WIREWRAP PINS
The procedures refer to wirewrap pins by card location and pin
number.
For example, A9S-0SA refers to pin gSA at wirewrap panel
location A0S.
The location and orientation of the pins of the
logic chassis wirewrap panel are explained 1n the RM05 Print Set.
3-23

3.13
CARD TEST POINTS
The card test points (Figure 3-11) are located on log ic cards in
either the logic or R/W chassis. These test points are located on
the component side of the card and consist of studs to which an
oscilloscope probe can be attached.
The test points may be
located anywhere on the component side of a card and are lettered
alphabetically, omitting letters I and o.
When viewed from the
component side with the connector at the right, the test ·points
appear as follows (refer to Figure 3-11).

I----...-CARD
CONNECTOR

T~
T~

9W138
Figure 3-11

Card Test Points

•

The test point in the lower left hand corner
ground and labeled z.

•

The upper test
labeled A.

point

3-24

the

left

also

is always
ground

and

a, c, D,

•

Other test points on the card edge are labeled
etc.

•

All other test points are assigned In reverse order from
the end of the alphabet (Y, X, W, etc.).
Y is the
nearest to the bottom right of tbe card and the letters
progress in reverse order from right to left in
successive rows from bottom to top.

The maintenance procedures refer to test· points by card location
and test point letter. This means that test point A on card A02
in the logic chassis is referenced as A82-TPA.
.
Only the test pc)ints located on the outer edge of the cards can be
accessed wi thout the use of a card extender, and only those test
points are called out in the procedures.
3.14 POWER SUPPLY TEST POINTS
The power supply control panel (Figure 3-12) contains test points
to measure certain voltage outputs from the power supply. These
consist of jacks into which a meter probe can be inserted to make
the required measurement.
3.15 PROCEDURE FOR MANUALLY POSITIONING CARRIAGE
Certain tests require m~nual operation of the positioner.
This
procedure should be performed only if the drive will not respond
or the desired results cannot be obtained with the servo under
logic .control.Improper positio,ni~9 .of .the heads (loading too
slow, hitting the forward stop or positioning heads in the loading
zone) will cause a servo fault condition and a possible head
crash. This could cause inaccurate results from any test that was
being performed. If a servo fault occurs, unload the heads, clear
the fault and repeat the operation being performed.
1.

Press START to stop the drive motor and unload the heads.

Remove the yellow leadwire from the voice coil.

Press START to spin-up the drive motor.

Remove the plastic shield to expose the voice coil.
CAUTION
Wait for 3. seconds for the drive motor
to come up to apeed.
Load the beads as
fast as possible to avoid having them in
a partially loaded position.

Carefully grasp the voice coil and load the heads.

3-25

lOJ6
Figure 3-12

Power Supp ly Control Panel Tes t Points
3-26

CAUTION
Move the colI at approxl.ate1y the ••• e
speed as It .oves under control of the
drive positioning logic •. Do not apply.
downward force while .ovlng the colI.
If
the
.pindle
power
is
lost,
immediately retract the beads.
6.

Move the po~itioner as described by applying a lateral
pressure to the coil.
CAUTION
Unload the heads as fast as,possible to
avolid baving them In a partially loaded
pos:Ltion.

When th(e tests are completed, manually unload the heads
to the fully retracted position.

Press START to stop the drive motor.
WARNING
Before reconnecting the yellow leadwire,
. make· certain ·that you.r fingers are clear
of the positioner.

Reconnect the yellow leadwire to the voice coil.

1~.

Press START to begin the drive motor and load the heads.

3.16
PREVENTIVE MAINTENANCE SCHEDULE
This paragraph gives the schedule for the preventive maintenance
procedures that must be performed on the .. drive to keep it
operating properly. The schedule is shown in Table 3-3.
Table 3-3

Interva1*
3 months
3 months
6 months
6 months
6 months
6 months
6 months
12 Months

Est. Time
(Minutes)
l~

1
2
5

20
9~
3~

Preventive Maintenance Schedule

Procedure
Clean primary air filter
Check +S volt and -5 volt output
Clean shroud and spindle
Clean and lubricate lockshaft
Clean carriage rails and bearings
Absolute air filter replacement
Head alignment check
Servo adjustment check

* Intervals

are maximum times.
Preventive maintenance may be
required more frequently depending on the level of dust
contamination in the operating area.
3-27

3.17
TESTS AND ADJUSTMENTS
This paragraph contains procedures describing all electrical
adj ustments that may be performed in the field.
Each of these
procedures descr ibes both the tests and adj ustments of a
particular aspect of drive performance.
The person performing these procedures should be thoroughly
familiar with operation of the drive and with all information in
Paragraph 3.1 of this manual.
3.17.1 +5 Volt and -S Volt Test and Adjustment
This procedure describes test and adjustment of the +5 and -5 volt
outputs from the regulator board (refer to Figure 3-13).
1.

Prepare drive for use with test software or FTU.

Command continuous seeks between cylinders 000 and 128.

Check and adjust +5 volts as follows:

Connect posi tive meter lead to A2JD94-04A on log ic
backpanel.

Connect negative meter lead to terminal marked ground
on front edge of regulator card.

Measured vol tage should be +5.1 (+0.05 vol ts) •
If
this requirement is not met, adjust the
bottom
potentiometer on the regulator card until voltage is
within specified limits.

Check and adjust -5 volts as follows:
a.

Connect positive meter lead to terminai marked ground
on front edge of regulator board.

Connect negative meter lead
A2JD94-01A on logic backpanel.

Measured vol tage should be -5.1 (+ ".05) vol ts.
If
this adj ustment is not met, adj ust- top potentiometer
on regualtor board until voltage is within specific
limits.

wirewrap

Prepare drive for return to on-line operation.

3.17.2 Head Alignment
Al ignment of the heads
below.

is checked

under

the

cond i tions

•

During initial installation of the drive

•

After replacing one or more head arm assemblies
3-28

1 isted

CARD
POSITION
A20

fVff4?'~
,.
:~

LOGIC CHASSIS
(CARD SIDE)

""
",
,

"
"
"

-1:
'I

::"
"

""
"""
"0'

.'.:

-v
GND

ANALOG
SERVO
CARD

)

~
~

REGULATOR

CARD

»CR17

+S VOLT
ADJUST
9W16

Figure 3-13

Voltage Regulator and Servo Adjustments

3-29

•

When misalignment of one or more heads is suspected (for
example, inability to read a pack written on another
drive) •

If it is determined that a head is misaligned, the head-arm is
adjusted to bring the alignment of the head within specifications.
Figure 3-14 is a flowchart summarizing the basic functions of the
head alignment check and adjustment procedure.
When performing head alignment, give special consideration to the
items listed in the following paragraphs.
3.11.2.1 Thermal Stabilization
In order to ensure accuracy
during head alignment, it is important that the drive, CE pack,
and FTU be at their normal operating temperature.
This requires
that all three be connected and allowed to operate (pack turning
and heads loaded to cyl inder zero) for a minimum of 60 minutes.
The CE pack requires only a 15 minute stabilization time when all
of the following conditions have been met.

•

Head alignment is bejng performed on more than one drive

•

The pack is taken immediately from another drive

•

The drive being tested has been operating with heads
loaded for a minimum of 60 minutes before the tests •

. 3. 11 • 2 • 2 Ali g.nm en t

To 0 1
Use 0 n 1 y the he a d ali g nm en t tool
specified in Table 3-1. Use of a different tool may cause damage
to head-arm or carriage. Always inspect the adjustment end of the
tool prior to use. The tool must be free of nicks and scratches
and must have a polished surface where it enters the carriage
alignment hole. If any aluminum deposits are present, polish the
tool surface with a crocus cloth. Any other polishing medium will
damage the tool. Do not use a defective tool. Repair or replace
the tool if damage exists.
When using the tool, position it so
that the pin in the end of the tool engages the alignment slot in
the head arm.
If anything more than a small amount of force is
requi'red to adj ust the head, the tool is probably binding in the
hole of the carr iage.
Ensure that the alignment tool is kept
perpendicular to the hole in the carriage at all times.

3.11.2.3 Carriage Locking - During the alignment procedure when
the heads are over the alignment track, the carriage locking pin
and ring assembly must be installed in the ALIGN TRACK LOCK hole
in the rail bracket assembly. This locks the carriage in the head
alignment position. Failure to install the pin and ring assembly
allows the carriage to retract if any emergency retract signal is
generated.
Since your hands are in the actuator area during the
head alignment procedure, the retract could be dangerous.

3-39

SET uP TEST

PERFORM
SERVO HEAD

AUJUST ALL R/W
HEADS UNTIL OFFSET
IS WITHIN A t75 .v
RANGE

orr!>E T
CH[C ~

YES

UNLOAD HEADS, TOROU[
HEAD ARM CLAMPING SCREWS
or H[ADS OFfSET >l~O mV
T04!1/2LBr·IN(O.50.1)
N·",). R[1uRN TO TflAO
24; (r;)

TROUBLESHOOT

19----.;...-:" SERVO CIRCuiT

onSET SERVO
HEAD ADJuSTM[to(T
SLOT AS R[OUIRfD.

THEN AL IliN Al L
R/W H[ADS TO

wlHd~

7; mV.

PERFORM RT2 S:EK.
TORQUE LOOSENED
CLAMPING SCREWS
TO 12 tI/2 LBF·IN
(1.4tO.l N.m) TH£h
CHECK THAT THEtR
OfFseT IS WITHlti
ACCEPTABLE RANGE

YES

PERFORM
R/W HEADS
OHSET
CHECK

EXERCISE HEAD ASSEMBLIES AND CHECK
~-----;:::======::;--I THAT OFFSET REMAINS
WITHIN ACCEPTABLE
ALIGNMENT
RANGE
WITHIN SPEC.
IS ANY
REMOVE TEST
/R/W HEAD OFFSET OUTSIDE ACCEPT~---"""'· SETUP. RETuRN
DRIVE TO

A8~RANG£&

OPERATION.

YES

9W14!!A

Figure 3-14

Basic Head Alignment Check and Adjustment Flowchart

3-31

CAUTION
Should an emergency retract condition be
generated when the locking pin is in the
ALIGN TRACK LOCK hole, the resul ts
listed below may occur.
•
•
•
•
3.17.2.4

Blown fuse
dc circuit breaker
Blown power amplifier transistors
Unretracted beads on a stationary CE
pack

~ripped

Initial Set-Up

Prepare
3.6.3).

Ensure that CE pack is thermally stabilized.

Connect oscilloscope to test points
(dibits) on head alignment card.

Connect test leads between head alignment card and FTU
null meter.

3.17.2.5

drive

for

use

with

FTU

(refer

paragraph

Z (ground)

and

Servo Head Offset Check

Set head alignment card S/RW swi tch to Sand X.1/X1
switch to S1. Refer to Figure 3-1 for entire check.

Command continuous seeks between cylinders 24eJ 1eJ
and 245 10 (365 8 ) for a minimum of 3eJ second~.

Command direct seek to cylinder eJeJ4.

Observe dibit pattern on oscilloscope.
similar to that shown in Figure 3-15.

Toggle PIN switch to both P and N positions and record
null meter readings.
If both P and N readings are less
than 100 mV, the X.l/Xl swi tch can be set to the Xl
position for more accurate readinqs.

Calculate head offset by using the following formula:
(P)

(N):II

(36eJ a )

should

OFFSET

Where P the is meter reading with PIN switch in P
position and N is the meter read ing wi th swi tch in N
Meter readings to the right of zero are
position.
positive and meter readings to the left of zero are
nega t ive.
3-32

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GND
VOLTf)/DIV
CH 1 • 1 V
CH 2 - NOT USED
TIME/DIV
A· 111 SEC
B· NOT USED
TRIGGERING
A - INTERNAL POSITIVE
B· NOT USED
PROBE CONNECTIONS (USE .10 PROBE)
CH
CH

1 TO DI81TS TEST POINT Y ON HD ALIGN CARD
2 NOT USED

:... ::... -~..l~...::..j~...:=. -.: =...:~...:=.. _:
CH I

u·

u..

. ..

··

Figure 3-15
Example 1:
Example 2:

Balanced Dibit Pattern

P •
(P)

+28;

(N)

P II: +20;
(P)

Exampl e 3:

P II:
(P)

(N)

-20;

N • +15

•

(+20)

N •

•

-15
(+20)

- (+15) • +5

- (-15) • +35

N .: +15

- (N) = (-20 ) - (+15) • -35

Record offset calculated in step 6.

~J-33

Evaluate servo head offset as follows:
•

If offset ranges between +60 mV and -60
acceptable. Proceed with head alignment.

mY,

•

If
offset
is
outside
+60
mV range,
it
is
unacceptable.
In this case, troubleshoot servo
system before proceeding with head alignment.

Command direct seek to cylinder 005 and
through 8.

repeat steps 4

10.

Add the offset readings from cylinders 004 and 005. This
sum should range between +75 mV and -75 mV.
If it does
not, troubleshoot servo system.
IF

Example 1:

P
=- -25; N
=1p) - (N) =- (1 25 )

-15

- (-15) = -10 mV

AND
p

•

+10;

~P) ,-! (N) =- (~10)

-10
(-10 ) =- +20 mV

THEN
(-10) + (+20) =- +10 mV

Sum is within +75 mV range and is therefore

EXAMPLE 2:

•

acceptable~

P
• +30;
N • -10
(-10) =- +40 mV
1p) - (N) • (t30)

AND
p

~P)

+15;

(N)

-30

= (~15) - (-30) =- +45 mV
THEN

(+40) + (+45) =- +85 mV
Sum is outside +75 mV range and is therefore unacceptable. Servo system troubleshooting is required.

3-34

11.

Command direct seek to cylinder 880 and
through 8.

12.

Command direct seek to cylinder 491.

13.

Install carriage locking pin into alignment hold
to Figure 3-16) and repeat steps 4 through 8.

OPTIMUM P SITION
OF SERVO HEAD
ARM ADJUSTMENT
SLOT

illf

repeat steps 4

HEAD ALIGNMENT

::~~
ALIGNMENT
ARM

SLOT

'k:sTANCES
APPROX.
EQUAL

ACTUATOR
HOUSING

&
CAUTION

ALIGNMENT TOOLS ON SOME DRIVES
CANNOT BE ROTATED MORE THAN lSO~
ROTATING TOOL BEYOND lSO·MAY
DAMAGE HEAD SLOT OR ALIGNMENT TOOL.

CARRIAGE
HEAD-ARM"
CLAMPING
SCREW
Figure 3-16

Head-Arm Alignment
3,-35

9W17-1

(refer

3.17.2.6

Read/Write Heads Check and Adjustment

Set R/RW awi tch to RW.
Observe that di bi t
similar to that shown in Figure 3-15.

pa t tern is

Calculate offset of all read/write heads by using same
method given in Steps 5 and 6 of Pargraph 3.17.2.5.

Remove carriage locking pin.

Evaluate read/write head offset as follows:
o

If all offsets range between +159 mV and -150 mV,
head al ignment is wi thin spec i fications.
Therefore,
proceed to Step 15 and restore drive to on-line
operation.

If any offsets are outside of the +150 mV range,
these heads are misaligned.
Proceed to Step 5.
However, before proceeding, ensure that no offset
exceeds a +300 mV range. If any offsets exceed this
range, excessive misalignment exists.
Transfer data
from all packs written with these heads to other
storage before proceeding with alignment.

Press START switch to stop drive motor and unload heads.

Loosen head-arm mounting screw securing heads that
require alignment and torque these screws to 0.5 +0.1 N·m
(4 +"1/2 lbf·in).

Press start switch to start drive motor and load heads.

Command direct seek to cylinder 491.
NOTE
Force exerted during adjustment can move
the heads from the alignment cylinder to
an adjacent cyl inder, resul ting in an
improper alignment.
Prevent this by
connecting a jumper fro. A97-11A (Seek
Error) to ground. Be sure to remove the
jumper before commanding the drive to
perform another seek.

Align heads as follows:
a.

Select head to be aligned.
WARNING
To prevent personal injury in case of an
emergency retract, install carriage
locking pin in head alignment hole prior
to positioning head alignment tool. Be
sure to rellove pin before next seek is
performed.
3-36

12.

Torque head-arm clamp screws of each head adjusted to 1.4
+0.1 N·m (12 +1/2 lbf-in.
While torquing screws, use
only B'traight-arm Allen wrench and keep it as perfectly
aligned as possible with Bcrews.

13.

Check each head adjusted to .ee if torquing screws
affected alignment_
If any heads, are outside +150 mV
range, re-adjustthem as directed in Steps 6 through 12.

14.

Perform the following to ensure that heads will remain
aligned under normal operating conditions.
a.

Command continuous seeks between cylind'ers
245 for a minimum of 30 seconds.

240 and

Unload and load heads at least twice.

Command direct seek to cylinder 291.

Check alignment of each head adjusted.
If any heads
are outside +150 mV range, repeat this procedure
starting wi th -Step 9. '

,lS. ' Prepare drive for return to on-line operation.
b.

Install head alignment tool 80 that tool pin engages
head-arm alignment slot (refer to Figure 3-16).

Observe oscilloscope and adjust ,head to obtain
balanced dibit pattern.
Pattern is balanced when
point A amplitude equals point B and point C equals
point D (see Figure 3-15).

Observe null meter and adjust head until the offset
reaches a range between +75 mV and -75 mV. Calculate
offset as described in Steps 5 and 6 in Paragraph
3.17.2.5.
Occasionally, a head cannot be aligned
because its adjustment slot is at the end of travel.
If this occurs, check position of servo head-arm
adjustment slot and, if necessary, recenter it.
It
should be noted that any slight adj ustment of the
servo head requires realignment of all read/write
heads.
Torque servo head to 1.4 +0.1 N·m (12 .:!:1/2
1 b f • in) •
Wh i 1 e
tor qui n 9
,8 ere ws ,
use
0 n1 y
straight-arm Allen wrench and keep it as perfectly
ali(~ned as possible with screws.
If care is not
taken during this operation, head may be pushed out
of 151 ignment.

Rep1eat Steps a through d for all heads to be aligned.

10.

Remove carriage locking pin and also remove jumper from
A07-11A (if it was installed).

11.

Press START switch to stop drive motor and unload heads.
3-37

3.17.2.7
Servo System Test and Adjustment - The procedure tests
and adj usts the servo system.
The servo system adj ustments and
their basic functions are listed below.
•

Coarse Posi tion Gain - Adj usts the gain of the veloc i ty
signal applied to the summing amplifier when the servo
system is in the coarse mode (cylinders-to-go equals more
than one hal f) • This adj ustment causes seek time to be
fast enough to meet the required specifications without
causing excessive overshoot past the desired cylinder.

•

Integrator Gain - Adjusts the gain of the velocity Signal
applied to the integrator.
The integrator output is
summed with the output from the O/A converter during the
last 128 cylinders of a seek.

•

Fine Velocity Gain - Adjusts the gain of the velocity
signal applied to the summing amplifier when .the servo
system is ·in fine mode (cylinders-to-go equals less than
one half).
This adjustment optimizes servo system
response by minimizing overshoot without overdamping the
system.

These adj ustments are interactive and therefore must be made in
the proper sequence. The proper sequence is shown in Figure 3-17.
The following describes test and adjustments of the servo system.
1.

Prepare the drive for use with test software or FTU.

Test and adjust coarse position gain as follows:
a.
b.

Command continuous seeks between cy1 inder 000 and
822 10 (1466 8 ).
Connect oscilloscope channel 1 to A07-03A (+On
Cylinder).

Trigger oscilloscope
(-Forward Seek).

negative

external

A07-07A

Set other oscilloscope controls as necessary to make
measurements required in Step e.

Observe display.
If distance between on-cylinder
pulses is not within 59 to 54 ms, adjust top
potentiometer on card A29 until this requirement is
met.

Test and adjust integrator gain as follows:
a.

Command continuous seeks between cylinders 000 and
128 1 " (20° 8 ).
3-38

PERFORM
COARSE POSITION
AIN ADJUSTMENT
PROCEDURE

PERFORM
INTEGRATOR
AIN ADJUSTMEN
PROCEDURE

PERFORM
FINE VELOCITY
AIN ADJUSTMEN
PROCEDURE

NO
YES
SERVO
ADJUSTMENT
PROCEDURES
COMPLETE

RECHECK COARSE
POSITION GAIN
ADJUSTMENT

YES

Figure 3-17

Servo System Adjustments Flowchart

3-39

Set up· oscilloscope as indicated in Figure 3-18 and
adjust it until the two sloped curves shown are
displayed.

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GND
LOST DISCONTINUITY
VOLTS/DIV
CH 1 - 0.5 V/CM
CH 2 - NOT USED
TIME/DIV
A - 0.5 MS/CM
B - NOT USED

FWD
SEEK

HORIZ DISPLAY
SET TO MAG X 10

TRIGGERING
A - POSITIVE EXT ON A 12-178 (+TS7)
B - NOT USED

REV
seEK

PROBE CONNECTIONS
CH1 TO A20-TPD (+ DESIRED VELOCITY)
CH2 - NOT USED
NOTE
IT IS NECESSARY TO INCREASE
VERTICAL SENSITIVITY TO MAKE
THIS MEASUREMENT.

seCONp TO LAST DISCONTINUITY

<30MV

~
IDEAL

CZ·02I7

Figure 3-18

Integrator Gain Waveform

NOTE
VOLT/CM and TIMB/CM settings have to be
changed to make measurement required in
step c.
c.

Observe the second to last discontinuity indicated in
Figure 3-18 and note that it has a difference of
+9.93 V (ignore the spike).
If it exceeds this
value, adjust bottom potentiometer on A2" so that it
meets these requirements.

3-40

1I0'1'E

k..

In step 4, the read operation 1. per. formed betw.en •••
This cause •
• nough delay between •• ets to provide
the proper dlaplay.
4.

Adjust fine velocity gain as follows:
a.

Set manual/sequential swi tch to manual and command
read operation to be performed in conjunction with
continuous seeks between cylinders 100 and 001.

Connect and
Figure 3-19.

set

oscilloscope

indicated

OVERSHOOT
UNDERDAMPED

OSCILLOSCOPE SETTINGS

./ \

.............; ...... ... ..-

. -

1\
~

LOGIC GND TO SCOPE GND

I-

,./ \ - .
'\ I ,.......-

VOLTS/DIV
CH1 - O.6V/CM
CH2 - NOT USED
TIME/DIV
A - 1 MS/CM
B - NOT USED

....

1"1 •••

... ..... . ..... .... .. ... ..... .. _.
-!
-. .

-I-

IDEAL

TRIGGERING
A - NEGATIVE ON A07·30A
(-SEEK)
B - NOT USED
PROBE CONNECTIONS
CH1 TO A19·TPC
(+ FINE POSITION ANALOG)
CH2 - NOT USED
UNDERSHOOT of

OVERDAMPED
CZ·028e

Figure 3-19

Fine Velocity Initial Check Waveform
3·.. 41

Referring to Figure 3-19, note that the displayed
signal settles out with maximum overshoot of less
than 59 mv. If overshoot exceeds this value, adjust
middle potentiometer on card in A2S. When adjustment
is complete, the display should resemble the ideal
waveform in Figure 3-19.

Command sequential forward seek from cylinder aaa
through 822
(1466 8 ) to be performed in conjunction
with a read.19

Note that the displayed signal is as shown in Figure
3-29 at each cylinder.
If overshoot exceeds sa mv at
any cyl inder, adj ust middle potentiometer on card in
A2S until this requirement is met.

Prepare drive for return to on-line operations.

3.18
TROUBLB ANALYSIS
This section describes procedures for checking various portions of
drive circuitry which are 9ritical to proper drive operation. For
complete trouble analysis information, refer to the RM0s Fault
Isolation Guide.

The purpose of the procedures is to assist maintenance personnel
in isolating problems causing improper drive operation. However,
. if the drive appears to be operating properly, failure to meet a
specification· given in this section does not in itself indicate
improper drive operation.
The procedure is divided into the following major areas:
•
•
•
•

Power Supply DC Voltage Output Checks
Servo System Checks
Read/Write System Checks
Miscellaneous Logic Checks

The person performing the maintenance procedures in this section
should be thoroughly familiar with operating the drive and with
all information in the General Maintenance section of this manual.
3.18.1 Power Supply DC Voltage Output Check
This procedure checks the dc power supply output voltages (refer
to Figure 3-12.)
This includes all voltages except +S volts and
-5 vol ts wh ich are chec ked in the +S vol t and -5 vol t test and
adjustment procedure.
1.

Prepare drive for use with test software or FTU.

Command continuous seeks between cylinders SSS and 128 10
(29° 8 ).

3-42

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOP,E GND
V.OLTS/DIV
CH' - O.IV/CM
CH2 - NOT USED
TIME/DIV
A·0.1 MS/CM
8 - NOT USED
TRIGGERING
A - EXT, A07·30A (-SEEK)
8 - NOT USED
PROBE CONNECTIONS
CH' TO A19·TPC (+ FINE POSITION ANALOG)
CH2 - NOT USED

.- ..-_.~

J \....

,..

....-...

.:.",-

·... _- ---- ---·
··

-: ~

···

....

··_.

i"'"

....

_ _A

.......-:

--. -- .. _-- -.... ---. -. --- .. -·
-...
-- ·

.,.-.

..:~

---- ------ -- --- --

-~-

CZ·0289

Fig Ulre 3-20

Fine Velocity Gain Final Check

Connect voltmeter ground
power supply panel.

Measure between ground jack and test jacks on power
supply control panel to check following DC vol tages as
listed in Table 3-4.

Disconnect voltmeter, then set up and connect oscilloscope as appropriate to measure ripple.

3-43

lead

ground

test

jack

Table 3-4

Power Supply Output Checks

OC Volts

Tolerance in Volts

Maximum Ripple in Volts

+46
-46
+9.7
-9.7
+20
+28

-2,+5
+2,-5
+1
+1
+2
+2

4.5
4.5

6..

NA
NA
1.0
1.0

Measure between ground jack and the following test jacks
on power supply control panel.
Ensure that peak to peak
voltage ripple is within the specified limits of Table
3-4.

3.18.2 Servo System Checks
The servo system checks consist of procedures tha t test var ious
points in the drive servo logic.
These procedures are divided
into two categories: (1) logic controlled checks (paragraph
3.18.2.1) and (2) manually controlled checks (paragraph 3.18.2.2).

The logic controlled
command the car r i age
system.

checks use the FTU or test software to
movement required for testing the servo

The manually controlled checks provide various tests that can be
per formed by manually posi tioning the carr iage.
These tests may
be necessary if problems exist such that satisfactory results
cannot be made through the use of the FTU or test software.
3.18.2.1
Logic Controlled Servo Checks
The
following
proced ures descr ibe var ious tests that can be per formed by using
the FTU or test software.

D/A Converter Output Check - Th is procedure checkoutput
of the O/A converter.
The O/A converter produces an
output tha t beg ins at some max imum val ue and steps down
as each track is crossed until the drive is on cylinder.
When on cyinder, the O/A output should be zero.
a.

Prepare drive for use wi th test software or FTU.

Connect and set up osc i lloscope as shown

in Figure

3-21.

Command

continuous

seeks

128.

3-44

between

cylinder

000

and

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE aND
WLTS/DIV

CH' - 5V/CM
CH 2 - NOT USED

TIME I DlV
1.- 5MS/CM
I-NOT USED
TRIGGERING
1.- NEG EXT. A07-07A (-FWD SEEK)
8- NOT USED
PROBE CONNECTIONS

eH I TO A20- TPB
eH 2 - NOT USE 0

IOV(t O.I)V -

-.. - - ----- - -- -- -- --. - -.. -- --.... --- ... - .. -. - .. --- _.. - - - -- -

CH2

9W21
Figure 3-21
d.

D/A Converter Output Waveform
Check that the observed waveforms are as shown in
Figure 3-22.
Note that by further expanding this
waveform it is possible to see the individual steps
prod uced as each track is crossed.
The steps should
be approximately equal and about 0.07 V in amplitude
(refer to Figure 3-22).

3-45

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GND

VOLTS IDIV
CM I - O. 1VI eM
CM 2 - NOT USE D
TtME I DlV
A- 5MS/CM
B - NOT USED

TRIGGERING

A- NEG EXT, A07-07A (-FWD SEEK)

B- NOT USED

PROBE CONNECTIONS
CH I TO A2 a- TPB
CH 2 - NOT USE 0

,.--_.-.
_.
--------- - - ----- .---- ----- --- -- -- --- -----

-I-

- '-

··..

I-

·..

lit

. .. . . . . .

...: ..~

.",

...

-I~

-I-l-

. . . . .. -.. ..
It

1- ••

·.
··..

.- .-

CH I
~

.. , , .,

...

I-I-

- - - -- ----- - - - -- -- --. --- -- -- --- ---- - _.. --- -- --- - - - -- ... ...:~ - ...
- ...
-- -

-I-

I-

Figure 3-22
e.
2.

Prepare

CH2

-~-

9W22
D/A Converter Output Wave~orm Expanded

drive

for

return

on-line

operation.

Cylinder Pulse Blanking Delay Check - This procedure
checks the delay preventing a cylinder pulse from being
generated as the drive moves off cylinder.
a.

Prepare drive for use with test software or FTU.
3-46

Command continuous seeks between cylinders 000 and
003.

Connect and set up oscilloscope as follows:
•

Connect

channel

1 to

A07-30B

(+Cylinder

Pul se

Blan~ing).

•

Tr igger posi ti've internal.

•

Set other controls as appropriate
measurements required in step 4.

make

Observe that the Cylinder Pulse Blanking delay is a
logic 1 for 950 (±50) microseconds.

Prepare drive for return to on-line operation.

Cylinder Pulse One Shot Check - This procedure checks the
duration
of
the
cylinder
pulses.
a.

Prepare drive for use with test software or FTU.

Command
003.

Connect and set up oscilloscope as follows:

continuous seeks between cylinders 000 and

•

Connect channel 1 to A07-22A (+Cylinder Pulses).

•

Trigger positive internal.

•

Set other controls as appropriate
measurements required in step 4.

make

Observe that the Cylinder Pulse one shot is a 1 for
10 (±2.5) microseconds.
•

Prepare drive for return to on-line operation.

Cylinder Pulse Switching Level Check - This checks the
levels at which the track-crossing detectors switch to
cause generation of a cylinder pulse.
a.

Prepare drive
FTU.

Command
822.

for

use with either test software or

continuous seeks between cylinders "''''0

3-47

and

Connect and set up oscillosco~e as indicated in
Figure 3-23.
Note that this figure actually shows
four different checks, each having a separate
resulting waveform.

Evaluate results as shown in Figure 3-23.

Prepare drive for return to on-line operation.

OSCILLOSCOPE SETTINGS

NOTE:

LOGIC GNO TO SCOPE GND

TIME IOtv
A- .2 MS/CM
B - NOT LlSED

TIME/DIY AND PROBE CONNECTIONS ARE
COMMON TO ALL THE FOLLOWING
WAVEFORMS.

. .. .. .

~-;V: ~...:~... :~ ··~k~· :~ :~ ~..
I\. ,.....,
,

PROBE CONNECTIONS
CH I TO A1S-09 B (+TRACK SERVO S IGNA~"
CH 2 - NOT USE D

+0.4(t.I)V/

CH I

.CH2

••••• ' •• _-1- •• -

VOLTS 101"

CH I ••• 5 V/ CM
CH 2 .• NOT USE D

""'

TRIGGERING

A- NEG EXT. AlS - 0 BB (+ CYL DE T B)
8- NOT USED

CHI

VOLTS 101"
CH I - • 1V/ CM
CH 2 - NOT USE D

CH2

TRIGGERING

A- POS EXT.
8- NOT USED

A1B-OBB

(+CYL

DET ·S)
9W23-1

Figure 3-23
5.

Cylinder Pulse Switching Level Waveform
(Sheet 1 of 2)

Fine Enable Switching Level Check - This procedure
verifies that the Fine Enable signal switches at the
proper tir.le.
rL'he Fine En-3ble sign.31 is turne,,~ on ·."'~1en
tracks-to-go are less than one and inte1rate1 velocity
rcaches a certain point.
a•

Pre pa red r i ve for use \-/ i t h t est

3-48

5 oft \-/ are

0 r

FT U•

Q§gLLOSCOPE SETTINGS

. . - .. ..
.. . ... ..
10··- • .... -....... ..... ..... ._ ... ... .. . ...... .... ... .. ... .. .~

VOLTS IOIV
CM I - • 5V / CM
CH2-NOT USED

TRIGGERING
A-NEG EXT.
B- NOT USED

"i~

CHI

......
A18-078 (+CVL OET A)

-0 4(f.l)V

~ ~.: ....... . ..... ...... ..

I-

•

. r-

• ..

V-

..4

CH2

..... . . _.. . ........ .... _.

...

- .
I

-j

......................... -_ ................. -. I
'CHI

O(± • .l)V
VOLTS IDlY
CH I - .1 V/ eM
CH 2 - NOT USE D
TRIGGERING

A-pas EXT. A18-078 (+CYL DET A)
B-NOT USED

9W23-2

Figure 3-23

Cylinder Pulse Switching Level Waveform
(Sheet 2 of 2)

and
Figure 3-24.

Connect

set

oscillosco:pe

indicClted

Conmand continuous secks between cylinders

~r1

in
anr.

"01.
d.

Observe that the wAveforms are as indicated in FiCJur':?
3-24.
Note that Fine Enable switches to a zero level
when integrated velocity is between +0.82 and +C.93 V
for forward seeks and -0.82 and -0.98 V for reverse
sl.~eks •

Prepare drive for return to on-line operation.

3-49

OSCILLOSCOPE SETTINGS
l.OGtC GND TO SCOPE GND
VOLTS IDlY
CH I - 5V /CM
CH 2 - a. 5V/ CM
TIME I DIY
A-O.5MS/CM

a-NOT USED

TRIGGERING

A-EXT NEG, A20-12A (-FWD SEEK)
USED

B- NOT

PROBE CONNECTIONS
CH I TO A20-10A (-FINE ENABLE)
CH 2 TO A2 0- TPG (+ I NT EGRAT ED VEL)

NOTE: SET DISPLAY MODE TO CHOP.

CH I

CH2

FWD

SEEK

9W24

Figure 3-24

Fine Enable Switching Level Waveform

3-59

Cylinder Delay Check - This procedure checks the delay
between the time the dr ive is on cyl inder and the On
Cylinder pulse is generated.
a.
b.

Prepare drive for use with test software or FTU.
Command

continuous seeks between

cyl inders 000 and

003.

Connect and set up oscilloscope as

follows~

•

Connect channell to A07-03B (-On Cylinder).

•

Trigger positive on A07-15A (+On Cylinder Sense).

•

Set other controls as appropriate
measurements required in step 4.

make

Observe that Not On Cyl inder is a log i c 1 for 1.75
(~0.35) milliseconds.

Prepare drive ,for' return -to on-line operation.

On Cyl inder Dropout Delay Check - This proced ure checks
_the dlel ay between the time the dr ive goes of f cyl lnde r
an~ when the On Cylinder signal drops.
NOTE
Place card A07 on card extender during
drive preparation procedure. Also place
chip clip on Ie in position A3. a.

Prepare drive for use with test software or FTU.

Command
003.

Connect and set up oscilloscope as follows:

continuous seeks between cylinders

000

and

•

Connect channel 1 to pin 3 of chip in pos i t 10 n
A3.

•
•

Tr igger negative internal.
Set other controls as appropriate to
measurements required
in step 4 of
procedure.

3-51

make
this

Observe that Not On Cyl inder is a logic I for 1.75
(±0.3S) milliseconds.

Prepare drive for return to on-line operation.

On Cylinder Pulse Check - This
duration of On Cylinder pulse.

procedure

measures

Prepare drive for use with test software or FTU.

Command continuous seeks between cyl inders eJeJeJ and
~eJl.

Connect and set up oscilloscope as follows:
•

Connect channell to A97-22A (+Cylinder Pulses).

•

Trigger positive internal.

•

Set other controls as appropriate to
measurements required in step 4 of
procedure.

make
this

Observe that On Cylinder is a logic 1 for eJ.3 (!eJ.eJ5)
milliseconds.

Prepare drive for return to on-line operation.

On Cylinder Switching Level Check - This procedure checks
the level at wh ich the On Cyl inder Sense sig nal goes
true. This should occur at each zero (track) crossing.
a.

Prepare drive for use with either test software or
FTU.

Set up and connect oscilloscope as shown in Figure

Command continuous seeks between cyl inders 00" and
eJ02.

Check that resulting waveforms agree with those shown
in Figure 3-25.

Set up and connect oscilloscope as shown in Figure

3-25.

3-2~.

CAUTION
While performing step 6, refer to
paragraph 3.15 and perform that enti re
procedure before proceeding to step 7.

3-52

Q,SCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GND
VOLTS/DIV

CH I - 0 . 2 V/ CM
CH 2 -NOT USED

TIME / DlV
A-O.IMS/CM
8-NOT USED
, TRIGGERING
A-POS EXT. AOS-3IB (+ON CYL SENSE)
B- NOT USED
PROBE CONNECTIONS
CH I TO AlB-09B (+TRACK SERVO SIGNAL)
CH 2 TO NOT USE D

O.4l(:!:,O.08)V

O.41(:!:,O. ~8)V ~

~........ -... -.-- ..... ... ----.--- ... --- ... -- ... -.
9W25
Figure 3-25

On Cylinder Switching Level - Waveform I

3-53

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GND
VOLTS/DIY
eH I - O. 5 V/ CM

eH 2 - NOT USE D
TIME / DIY
A-O.2MS/CM

B-NOT USED
TRIGGERING

A- NEG EXT, AD8-3IB (+ ON CYL

SEN~E)

B- NOT USED

PROBE 'CONNECTIONS
CH I TO A18-09B (+ TRACK SERVO SIGNAL)
C' 'I TO N0 ~ uC\ E0

CH I

+O.95(!..1)V

-O.95(!..1)V
CH2

9W26
Figure 3-26

On Cylinder Switching Level - Waveform II

Observe display while manually moving carriage in
forward and reverse directions. Check that resulting
waveforms agree with those in Figure 3-27.

Prepare drive for return to on-line operation.

3-54

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GNO
YOLTS/DtV

CH I - O.IV/CM (READ SCALE AS IOOMV)
USED

CH 2 - NOT

T.ME I DlV
A- 2MS/CM

e - NOT USED
TMGGE~NG

(POSITIVE/EXTERNAL)

A- I NDE X

I-NOT USED
PROBE CONNECTtONS
eM I TO A19-TPC (FINE POS ANALOG)
eM 2 - NOT USE 0

NOTES:
1. MORE THAN NORMAL ,RUNOUT RESULTS
IN THE WAVEFORM HAVING A 60 Hz
SINUSOIDAL COMPONENT AS SHOWN ON
WAVEFORM A. AS AMOUNT OF RUNOUT
INCREASES, THE PEAK TO PEAK AMPLITUDE
OF THE 60 Hz COMPONENT INCREASES.

2. NORMAL RUN OUT IS SHOWN ON WAVEFORM B.
IN THIS CASE, THE AMPLITUDE OF THE 60Hz
SINUSOIDAL COMPONENT IS LESS THAN
400MV PEAK TO PEAK.

Figure 3-27
10.

9~27

Track Following Check Waveform

One Track Seek Time Check - This procedure checks the
time it takes for the positioner to move from one track
to another.
a.

Prepare drive for use with test software or FTU.

Command drive to perform one cylinder sequential
forward seek, starting at cylinder 000 and ending at
822. Perform a read operation between each. seek.

Connect and set up oscilloscope as follows:
•

Connect channell to A07-03A (+00 Cylinder).

•

Trigger
Seek) •

•

Set other oscilloscope controls as appropriate
for making measurements required in step 4.

negative

3-55

internal

on A07-07A

(-Forward

11.

Observe that signal is low.for 8 millseconds or less.

Prepare drive for return to on-line operation.

Positioner Offset Voltage Check - This checks the offset
level produced by a servo offset command.
The
measurement is made on the Track Servo signal which
normally has an average dc level of zero when the drive
is on cylinder.
a.

Prepare drive for use wi th ei ther test software or
FTU.

Command direct seek to cylinder

Connect and set up oscilloscope as follows:
•

Connect channel
Signal).

•

Set channel A sweep tr igger mode to AUTO.

•

Set other controls as appropriate
measurements required in step 4.

4~0.

AlS-09B

(+Track

for

Servo

making

NOTE
Measure average dc level in steps 4 and
5.

12.

Command carriage offset plus (forward offset)
observe that the scope indicates +0.6 (±0.l) V.

and

Command carriage offset minus (reverse offset)
observe that the scope indicates -0.6 (±~.l) V.

and

Prepare drive for return to on-line operation.

Track Following Check - This procedure checks the ability
of the heads to accurately follow the track.
Inability
to stay on track may be caused by excessive runout of the
disk pack or spindle assembly. Runout is the degree to
which a rotating disk pack wobbles off its center of
rotation.
Inabil i ty to stay on track is also caused by the servo
logic beingunaole to respond to allowable runout.
If the heads do not accurately follow the track, read
errors may occur and the drive may also intermittently
drop the On Cylinder signal.

3-56

Prepare drive for use with test software or FTU.

Command direct seek to cylinder 400.

Connect and set up oscilloscope as follows:
•

Connect channel
Analog).

1 to A19-TPC

(Fine

Position

•

Trigger positive external on A06-TPC (Index).

•

Set other controls as appropriate
observations required in remainder
proced ure.

to
of

make
this

Observe display and refer to Figure 3-27 .As runout
increases, waveform sinusoidal amplitude increases.

Interpret display as follows:
•

If ampli tude of 60 Hz sinusoidal component of
waveform exceeds 400 mV peak to peak, it is
excess i ve and a problem ex i sts wi th either dr i ve
or disk pack. In this case, note point at which
waveform syncs with Index, and proceed to step 6.

•

If waveform sinusoidal amplitude does not exceed
400 mV the drive or disk pack does not have
excessive runout. In this case, proceed to step
11.

Press START switch to stop drive motor
heads.

Note posi tion of disk pack on spindle, remove disk
pack, rotate it 90 degrees (1/4 turn) in either
direction and reinstall it on the spindle.

Press START swi tch to spin-up dr ive motor and load
heads.

Command direct seek to cylinder 400.
NOTE
Index and Pi ne Pos i tion signal s are
der ived from servo dibi t tracks on the
disk pack.
Zero phase shift between
these signals indicates a no spindle
runout condi tion.
This is a dynamic
check performed wh.11e the disk pack is
rotating with respect to the spindle.

3-57

and

unload

Compare the phase position of waveform displayed with
phase position of waveform observed in step.
Interpret results as follows:
• If phase relationship of both waveforms
coincide, disk pack or servo system is cause of
excessive runout •
• If phase relationship of both waveforms do not
coincide, spindle or servo system is causing
excessing runout.

k.
13.

14.

Prepare drive for return. to on-line operations.

Track Servo Amplitude Check - This procedure checks the
amplitude of the track servo dibits signal that inputs to
the track servo circuit.
a.

Prepare the drive for use with test software or FTU.

Connect and
Figure 3-28.

Command direct seek to cylinder 000 and observe peak
to peak amplitrude of the waveform.

Command direct: seek to cyl inder 822 and observe peak
to peak amplitude of the waveform.

Check that the waveform observed in steps 3 and 4 is
between 0.3 and 1.5 V peak to peak. Also note that
the waveform of step 3 has the largest amplitude.

Prepare drive for return to on-line operation.

set

osc i lloscope

indicated

Velocity Transducer Gain Uniformity Check - This checks
the output of the velocity transducer by monitoring the
sawtooth output of the velocity integrator.
Note that
the positive sawtooth waveforms are produced during
forward seeks and the negative waveforms during reverse
seeks.
a.

Prepare drive for use with test software or FTU.

3-58

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GND
VOLTS/DIV
CM I - O. 5 VI CM
CH2-0.5V/CM
T.ME / DlV
A- IIJS CM
B - NOT USED
TRIGGERING
1.- INTERNAL

I-NOT USED

NEGATIVE

PROBE CONNECTIONS
CM I TO A18-25B (-DIBITS)
CM 2 TO A18 - 23 B (+ 0 I BIT 5 )

NOTE: SET DISPLAY MODE TO ADD AND INVERT ONE CHANNEL

·
-h-

-..._... --·
.......
..
--_.
-1----- ----- -- --- --- -- -.. ------ -~

1-'

•3 TO
1.5V PP

'r ~

-...

-,-

J. .

U
....

CH I

· r'
~
·
·."----- .'. -- ... .. J ---- - -----. CH2
-I-l-

L .. J.. --~-- . ---- _. .- ·

-l-

I-

-I-

~t:-

-- -...

-,-

9W28

Figure 3-:28

Track Servo Amplitude Waveform

3-59

Connect and
Figure 3-29.

set

oscilloscope

indicated

OSCILLOSCOPE. SETTINGS
L.OGIC GND TO SCOPE GND
VOLTS IDIV
CH I - 1V/ CM
CH 2 - NOT USE D

TIME I DlV
A- O.5MS/CM
8 - NOT USED

TRIGGERING

A- EXT POS. A12 - 1 78 (T

B- NOT USED
PROBE CONNECTIONS
CHI TO A20-TPG (+INTEGRATEO
CH 2 - NOT USE 0

VELOCITY)

SECOND TO LAST POS. RAMP
LAST RAMP

CH I

CH2

SECOND TO LAST NEG. RAMP

Figure 3-29

Velocity Gain Uniformity Waveform

3-fi9

9W29

Command
822.

continuous

seeks

between cy1 inder s

"""

and

Observe waveforms as shown in Figure 3-29 and
ev,aluate the second-to-last positive and negative
ramps as follows:
•

The amplitude of each ramp must range, in its
respective direction between 1.8 V and 2.2 V.

•

The difference in amplitude between the two ramps
must range between +0.3 V and -0.3 V.

3.18.2.2
Manually Controlled Servo Checks
This procedure
describes testing the servo system while manually positioning the
carriage.
1.

Prepare drive as follows:
a.

Press START switch to stop drive motor.

Set MAIN AC circuit breaker to OFF.

Raise top cover.

Put logic chassis in maintenance position.

Remove logic control of voice coil by disconnecting
yellow lead wire at voice coil.
CAUTION
Make
sure
the
carriage
is
fully
retracted.
Refer to the procedure for
manually positioning the carriage.

Check that the output of the summing amplifier is at 0
volts before drive motor is energized by performing the
following procedure:
a.

Set oscilloscope
V/CM.

vertical

sensitivity control

Set oscilloscope
MS/CM.

horizontal

sweep

c•

Set 0 sci 11 0 s cop e
running) •

t rig 9 e r

c on t r 0 1

Connect oscilloscope channel
Amp Output).

A to A20-25A

Set: MAIN AC circuit breaker
voltage remains at D V.

to ON and observe that

control
to

AUT 0

0.1

(f r ee

(+Summing

3..

Check that the output of the summing amplifier goes to
-10 V when drive motor gets up to speed by performing the
following procedure.
a.

Connect and set up oscilloscope as in step 2.

Press START swi tch to start dr ive motor and observe
that the summing amplifier output drops to -10 V when
drive motor gets up to speed (approximately 30
seconds) •
CAUTION
Refer to paragraph 3.15 before loading
and posi tioning heads as deser ibed in
the following steps.

Manually load heads.
positioning carriage.

Check velocity transducer and amplifier as described in
the following:
a.

Refer

to discussion on manually

Set up oscilloscope as follows:
•

Vertical sensitivity to 0.5 VIM

•

Horizontal sweep to IS MS/CM

•

Trigger

•

Connect channel A to A20-TPE (+Velocity).

~ontrol

to AUTO (free running)

Manually move carriage toward cylinder 822 (forward
direction). Signal should go negativ·e and amplitude
should increase as speed of carriage increases.

Manually move carr iage toward cylinder 000 ( reverse
direction).
Signal should go positive and amplitude
should increase as speed of carriage increases.

Check Fine Position Analog signal.
If signals observed
are as specified in the following, it indicates that the
track servo and servo head are functioning properly.
a.

Set up and connect oscilloscope as follows:
•

Set vertical sensitivity control to lV/CM

•

Set horizontal sweep control to 19M5/CM

•

Set trigger control to AUTO (free running)

•

Connect channel
Analog).

A to

A19

TPC

(Fine

Position

Observe an approximate 3.8 V peak-to-peak signal when
moving carriage in either forward or reverse direction. When signal 'is at e V, drive is on cylinder.

Check polarity of Fine Position Analog signal.
If
observed signal s are as spec i fied, it ensures tha t the
Fine Position Analog signal has the proper polarity when
it is applied to the Fine Gate.
a.
b.

Oscilloscope s.ettlngs and connections are same as in
previous step.
Move posi tioner back until heads contact head cams.
not unload heads.

Observe that Fine Position Analog signal is at 0 V.

Manually move carriage slowly forward and observe
that signal first goes positive as it crosses the
reverse end-of-travel area, then moves alternately
posi ti ve and negative as servo head sta r ts cross i ng
tracks.

Chec k summing ampl i f ieroutput.
If signal sobserved in
the following are as specified, it indicates that the
proper signal is being gated to the summing amplifier,
fine mode Is enabled, and Velocity and Fine Position
Analo~1 signals are properly summed.together.
a.

Connect and set up oscilloscope as follows:
•

Set vertical sensitivity control to 5 V/CM

•

Set horizontal sweep control' to 20MS/CM

•

Set trigger control to AUTO (free running)

•

Connect channel
Output) •

A to

A2e-25A

(+Summing

Amp

Move carriage in forward, and then reverse direction.
Signal should be that of step 6 superimposed on
signal of step 5.
The signal should clamp at
approximately :tIe V, depending on the direction of
travel.

3-63

Check the 'power ampli fier output.
are as spec if ied in following,
functioning properly.
a.

If signals observed
po we ram p li fie r i s

Connect and set up oscilloscope as follows:
•

Set ver tical sensi tiv i ty cont rol to 2 V/CM (use
10X probe)

•

Set horizontal sweep control to 10MS/eM

•

Set trigger control to AUTO (free running)

•

Connect channel A to yellow leadwire which was
disconnected from voice coil.

Move carriage in forward, and then reverse direction
and observe signal switching from +46 to -46 V.
CAUTION
Refer to paragraph 3.15 before manually
unloading heads.

10.

Manually unload heads.

11.

Press START switch to stop drive motor.

12.

Set MAIN AC circuit breaker to OFF.

13.

Reconnect yellow lead wire to voice coil.

14.

Prepare drive for on-line operation.

3.19
READ/WRITE SYSTEM CHECKS
The read/write system checks consist of procedures checking
basic read/write capability of the drive.

the

3.19.1 Write Circuit Checks
This procedure checks three points in the write circuits (refer to
Figure 3-30).
If the signals at these points are correct, it
indicates the circuits are performing their basic function.
1.

Prepare the drive for use with test software or FTU.

Command drive to write a 1010 bit pattern on the disk.

Check the inputs to the NRZ to MFM conver ter and wr i te
compensation circuits.
Timing relationships between
these signals (NRZ data and 9.67 MHz enable signal) must
be correct before proper NRZ to MFM conversion and write
compensation can be performed.

3-64

9.67 MHZ ENABLE SIGNALS WHICH
PROVIDE BASIC TIMING.

WRITE COMPENSATED MFM
DATA WHICH PROVIDES INPUT
TO WRT DRIVER CIRCUITS.

TESTED BY: STEP 3

TESTED BY: STEP 4

A13-108

WRT CbOCK

E02-TPU

NRl TO MFM
CONVERTER
AND WRT
~:OMPENSAT tON
CIRCUITS
AI3

NRZ DATA

WRITE
DRIVE
CIRCUITS
£02

LINE
RCVR
£02

TO HEADS

AOStSB

E02-TPT

NRZ DATA RECEIVED
FROM CONTROLLER.

FEEDBACK SIGNAL FROM OUTPUT OF
WRT DRIVER WHICH PROVIDES CHECK
OF WRT DRIVER AND HEADS.

TESTED BY: STEP 3

TESTED BY: STEP 5
9~149

Figure 3-30

Write Circuits Test Points

Connect and set up oscilloscope as shown
3-31.

Observe that signals
shown in Figure 3-31.

have

timing

in Figure

relationships

Check input to write driver circuits.
This checks
compensated MFM data input to write toggle flip-flop.
a.

Move oscilloscope channel 2 probe to E02-TPU.

Observe that signals have approximately the relationship shown in Figure 3-32, and that channel 2
signal has proper polarity.

3-65

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GNO
VOLTS IDIV
CH I - 0 • 2 V/ CM
CH 2 - 0 • 2 V/ CM
TIME I DlV
A- 2MS/CM

a-o.os S/CM

TRIGGERING

A- +EXT, A06-TPC (INDEX)

B- - I NT

PROBE CONNECTIONS (1 0 X PRO BES )
CH I TO A13 - TPE (N RZ DA TA)
CH 2 TO. A13 - TPB (W RT STROB E)

NOTE: SET TO DISPLAY MODE TO ALT AND TRIGGER MODE TO CH 1 ONLY.
ALSO SET HORIZONTAL DISPLAY TO B (DELAYED SWEEP)

1-E------=~-103(± 5) NS

CH I

50 Ct351 NS----+----+--~~..

CH2

9W30
Figure 3-31

NRZ Write Data Input Waveform

3-66

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GND
VOLTS/DIV
CH I 2 V/ CM
CH 2 - O. 2V/CM

TIME I DlV
A- 2MS/CM
B - 0 • 0 5~S / CM
TRIGGERING
A- + EXT tAO 6 .. TPC (+ I N0 EX)

B- - I NT

PROBE CONNECTIONS (1 0 X PRO 8 ES )
CH I TO A13 - TPE (N RZ DA TA )
CH 2 TO E02· TPU

NOTE: SET DISPLAY MODE TO ALT AND TRIGGER MODE TO CH 1 ONLY.
ALSO SET HORIZONTAL DISPLAY TO B (DELAYED SWEEP)

CHI

~~'I

CH2

9W31

Figure 3-32

Write Driver Input Waveform

3-67

Check output of write driver circuits. This ensures that
write driver is sending data and that the head is
functioning.
a.

Move oscilloscope channel 2 probe to E02-TPT.

Observe that signals are approximately as shown in
Figure 3-33.
OSCILLOSCOPE SETTINGS
LOGtC GND TO SCOPE GND
VOLTS IDIV
CH I - O. 2 V/ CM
CH 2 - 0 • 2 V/ CM
TIME I DlV
A- 2MS.CM
B- O.05~S/CM
TRIGGERING
A- + EXT tAO 6 - TPC (+ I N0 EX)

B- - I NT

PROBE CONNECTIONS (lOX PRO B ES )
eH I TO A13-TPE (NRZ DATA)
CH 2 TO EO 2- TPT

NOTE: SET DISPLAY MODE TO ALT AND TRIGGER MODE TO CH 1 ONLY.
ALSO SET HORIZONTAL DISPLAY TO B (DELAYED SWEEP)

CH I

CH2

9W32

Figure 3-33

Write Driver Output Waveform
3-68

Prepare drive for return to on-line operation.

3.19.2 Read Circuit Checks
This procedure checks the basic operation of the read circui ts.
Refer to Figure 3-34.
If the observed signals are correct, it
indicates these circuits are performing their basic functions.
RD REFERENCE ClK SIGNALS
PROVIDE INPUT DURING PlO
SYNCHRONIZATION AND AM AREAS.
TESTED BY: STEP
5

AI5-238

AI4-0SB

DETECTION

HEADS
___

E03

TESTED BY: STEP 6

~5-24B----

TESTED BY: HEAD AMPLITUDE TEST

RD/WRT~~~~T~

DIGITAL NRZ DATA SIGNALS
SENT TO CONTROllER.

At4-04B

ANALOG

PLO AND

TO DIGITAL

}

DATA

CONVERTER
AI4

A15-27B

SEPARATOR~--9"_'"
t-I---9"-....

AI5

CONTROLLER

A15-26B

ANALOG DATA SIGNALS DERIVED
FROM SIGNALS DETECTED BY
RD/WRT HEADS.

DIGITAL MFM DATA DERIVED
FROM ANALOG DATA SIGNALS.

RD ClK SIGNALS
SENT TO CONTROLLER.

TESTED By: STEP 3

TESTED BY: STEP 4

TE~TED

BY: STEP 6
9W150

Figure 3-34

Read Circuits Test Points

Prepar.e drive for use with test software or FTU.

Command drive to write 1010 bit pattern on disk.

Command drive to read 1010 bit pattern.

Check analog data ,input to the analog to digital
converter circuits. If signals are correct, it indicates
that the analog data detection circuits are functioning.
set

Connect and
Figure 3-35.

Observe that signal is approximately as shown in
Fig ure 3-35 with approximately 200 ns between zero
crossings.

3-69

osc i lloscope

indicated

a•

OSCILLOSCOPE SETTINGS·
LOGIC GND TO SCOPE GND
VOLTS IDIV
CH I - 0 • 1 V/ eM
CH 2 - o. 1 V/ CM
TIME I DlV
A- 2MS/ CM
8-0.05 S/CM

TRIGGERING
A- + EXT tAO 6 - TPC (+ I NO EX)

B- - I NT

PROBE CONNECTIONS (1 0X PRO 8 ES)
CH I TO A14-0B8 (-ANALOG DATA)
CH 2 TO A14 - 0 7 8 (+ ANALOG 0 ATA)

NOTE: SET DISPLAY MODE TO ADD AND INVERT ONE CHANNEL.
ALSO 5ET HORIZONTAL DISPLAY TO 8 (DELAYED SWEEP)

"ZERO CROSSINGS /

Figure 3-35

9W33

Analog Read Data Waveform

3-70

Check output of data latch flip-flop.
If observed
signals are correct it indicates high and low resolution
channels and data latch flip-flop are functioning.
a.

Connect and set up osc illoscope as shown In Fig ur e
:~-36 •

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GND
VOLTS/DIV
eH I - O. 1 V/ CM
eH 2 - 0 • 1 V/ CM
TIME / DIV
A- 2MS/CM
B-O.05S/CM
TRIGGERING

A- + EXT. A0 6 - TPC (+ I NO EX)

B- - I NT

PROBE CONNECTIONS (lOX PRO 8 ES )
eH I TO A14-038 (+RD DATA)
eH 2 TO A 14 - 04 8 (- ROD ATA )

NOTE: SET DISPLAY MODE TO ADD AND INVERT ON CHANNEL.
ALSO SET HORIZONTAL DISPLAY TO B (DELAYED SWEEP)

-- - - -- ..:··· - -- -_
..
--.-._-- - .. ---- .. - .. -- .. - ---- -- --..
-- .. --- .. -.
~

--~

'"""

... eo _ _ _

·0'"

.. -

,,'"

-y

. . 'i' .. . . . . . . .
,

• -.

.....

.
··
···
·

--.....

T'-T~. ~ --.T

-- -- r-

I•

.., ,

-- --- - - --. - ----· -----. ---- ------ ----- - -- -- - - .:· - - -

,M'" _ _ ..

Fig ure 3-36

I-

Data Latch Output Waveform
3-71

9W34

Observe

that

signal

F i9 ure 3-37.

aproximately

shown

OSCILLOSCOPE SETTINGS
LOGIC GND TO SCOPE GND
VOLTS/DIY
CH I - 0 • 2 V/ CM
CH 2 - 0 • 2 V/ CM
TIME / DIY

A- 2MS/ CM
B - 0 • 05,uS / CM
TRIGGERING

A--EXT, A15-12B (-READ GATE)
B--INT

PROBE CONNECTIONS (lOX
CHI TO A 1 5 - 2 7 B
CH 2 TO A15 - 26B

PRO BES)

NOTE: SET DISPLAY MODE TO ALT AND TRIGGER MODE TO CH 1 ONLY.
ALSO SET HORIZONTAL DISPLAY TO B (DELAYED SWEEP)

......- - -...-103 (! 10) NS

CH I

CH2

....--.....-51.6(tS)NS

Figure 3-37

Read Data to Read Clock Timing

3-72

9W35

Check frequency of Read Reference Clock signals.
a.

Connect and set up oscilloscope as shown in Figure
3-35 except move channel 1 probe to AlS-24B (+Read
Reference Clock) and channel 2 probe to A15-23B
(-Read Reference Clock).

Observe that the displayed signal has a frequency of
approximately 4.84 MHz.

Check the read data to read clock timing relationship.
If signals are correct, it indicates read circuits are
generating the proper Read Data and Read Clock signals.
a.

Connect and
3-:37.

set' up oscilloscope as shown in Figure

Prepare drive for return to on-line operation.

3.29
HEAD AMPLITUDE CHECK
This procedure verifies that the read signal has sufficient
amplitude to be reliably processed by the read logic.
Since
amplitude decreases as recording frequency increases, the minimum
amplitude, in r-IFM recording, is obtained when an all "0" or all
"1" patterns are being read.
The minimum amplitude is tested
first.
Minimum recording frequency and the greatest amplitude is
obtained by an alternate "1010 ••• " pattern.
This amplitude is
al so tes ted.
1.

PreparE! the drive for use with test software or FTU.

Command direct seek to cylinder 822 and write an all "15"
pattern.

Connect and set up oscilloscope as follows:

Trigger negative external on A06-TPC (Index)

Connect channel 1 to E03-TPB

Connect channel 2 to E03-TPC

Set DISPLAY MODE to ADD and invert one channel

to values
Set
VOLTS/CM and
TIME/CM controls
appropr iate for making measurements required in
remainder of this procedure.

Command drive to read, select each head in turn and
measure ampl i tude of read signal for each head.
Thi 5
ampl i tude should be a minimum of 130 mV peak to peak.

3-73

Command direct seek to cylinder
"1~1~1~ ••• " pattern with all heads.

Command dr ive to read, select each head in turn, and
measure ampl i tude of read signal for each head.
This
amplitude should be a maximum of 11~~ mV peak to peak.

Prepare drive for return to on-line operation.

3.21

~~l

and

write

MISCELLANEOUS LOGIC CHECKS

3.21.1 Index Timing Check
This procedure ensures that Index is present and has the proper
pulse width.
It also checks the time between successive Index
pulses which is an indication of disk pack rotational speed.
1.

Prepare drive for use with test software or FTU.

Connect and set up oscilloscope as follows:
a.

Connect channel 1 to A06-TPC (+Index).

Trigger internal positive.

Set other controls as appropriate
ments required in steps 3 and 4.

to make measure-

Observe that Index is a logic 1 for 2.5 (±0.3) us.

4.,

Observe tha t
ms.

5.,

Prepare drive for return to on-line operation.

time between indexes is approx imatel y 16. 7

3.21.2 Speed Sensor Output Check
This procedure checks the output of the speed sensor to ensure
that it has the proper polarity and is of sufficient amplitude.
1.

Prepare drive for use with test software or FTU.

Connect and set up osai1loscope as follows:
a.

Connect channel 1 to A17-71A (speed sensor output).

Trigger positive internal.

Set other controls as necessary to make measur emen t
in step 3.

3-74

Check oscilloscope waveform for the following:
a.

Sicope trace should first go
negative with respect to ground.

positive

and

then

If not, wiring to speed sensor is reversed.
Correct
the wiri.ng to speed sensor and recheck polarity of
signal. If waveform is correct, 90 to step 38.
b.

Observe amplitude of waveform on oscilloscope.
Signal should have positive and negative amplitudes
of at least 9.6 V. If not, recheck speed sensor gap.

Prepare drive for return to on-line operation.

3-75

CHAPTER 4
REPAIR AND REPLACEMENT

4.1

INTRODUCTION

This chapter contains information pertinent to the mechanical
repair and replacement of the RM05 subsystem field replaceable
units (FRU).
It also describes the associated adjustments
required to maintain proper operation of the RM"5 subsystem.
The procedures in this chapter are arranged alphabetically
a c cor din g t o t he ass em b 1 Y 0 r com po n e n t ass 0 cia ted wit h the
procedure.
All procedures assume that the drive and adapter are
installed in line with other drives and adapters, permitting
access only from front or rear.
If the cabinets are not installed
in this position, certain procedures may be performed more ·easily
by removing side panels and accessing the FRUs from the side.
Figure 4-1 locates the FRUs
in the RM05 which require a
replacement and/or adjustment procedure.
Additional parts data,
including illustrations and part numbers, may be obtained from the
RM05 Illustrated Parts Breakdown.
4.2
ACTUATOR A,SSEMBLY REPLACEMENT
The actuator is located on the deck
4-1 VDE and NON-VDE versions.

assembly.

Refer to

Figure

The following describes the entire procedure for replacing the
actuator assemb1y.
Figure 4-2 is an exploded view of the deck
assemblies involved in actuator replacement.
1.

Remove power from drive as follows:
B.

Press START
heads,

switch

stop drive

Set MAIN AC circuit breaker to OFF.

motor

Remove disk pack.

NOTE
If the drive is installed in line with
other drives, it lDay be necessary to
move the drive out of line to remove the
top cover.

4-1

and

unload

PACK
ACCESS
COVER
SWITCH
HEAD CAM
HEAD-ARM
ASSEMBL I ES __
SPINDLE
LOCKSHAFT

HEADS
LOADED
SWITCH
MAGNET
/ VELOCITY
TRANSDUCER
READ/WRITE
CHASSIS
VOICE COIL
FLEX LEADS

PACK / ,
ACCESS
COVER
SOLENOID
PARKING
BRAKE

BLOWER
MOTOR
F 19 ure 4-1

9W36-1

Assembly Locator NON-VDE (Sheet 1 of 2)

4-2

STATIC GROUNDSPRING
'SPEED SENSOR
SWITCH
ASSEMBLY

9W36-2

Figure 4-1

Assembly Locator NON-VDE (Sheet 2 of 2)

4-3

MAGNET
READ/WRITE
CHASSIS

LOGIC

PACK
ACCESS
COVER
CATCH

PARKING
BRAKE

BLOWER
ASSEMBLY

PACK
ON
SWITCH

SPEED
SENSOR
CZ·0834

Fig ure 4-1A

Assembly Locator VOE (Sheet 1 of 2)

4-4

STATIC GROUNDSPRING
SENSOR
SWITCH
ASSEMBLY
MOTOR

~ APPLICABLE TO VDE UNITS ONLY
BRAK'E ASSEMBL Y ~

CZ·0645

Figure 4-1A

Assembly Locator VDE (Sheet 2 of 2)

4-5

CAP

MAGi~ET

STOP MOUNT
VOICE COIL
STOP PLATES
STOP RO
CARR lAG

ACTUATOR

HEADS

--k/

FLEX LEADS
MOUNTING
BRACKET
VOICE COIL
FLEX LEADS,
REAR DECKJ
SEAL

/ ' REAR DECK

~ t-,~===~
SERVO
PREAMP

PLATE

~,.,...-

READ/WRITE
CHASSIS

9W37

Fig ure 4-2

Actuator Replacement

Remove cabinet top cover.

4 ..

Remove deck cover.

Remove pack access cover.

6 ..

Remove shroud and shro ud cover.

4-6

CAUTION

The magnetic field generated by the
magnet is very strong- Permanent damage
will occur to any watch brought near the
magnet.
7.

Make note of voice
disconnect leadwires.

Disconnect velocity transducer cable plug P4.

Cut ceble ties securing voice coil and heads-loaded
switch leadwires to side of actuator housing.

Ie.

Remove two screws and washers securing heads-loaded
switch to actuator housing, then remove switch and set it
aside leaving leadwires connected.

11.

Move servo preamp housing as follows:
a.

coil

leadwire

connections

and

Remove two screws secur ing cover
and remove cover,

to preamp housing

b •. Disconnect servo head cable plug
board,

from servo preamp

Remove two
deck,

screws securing servo preamp housing

Move housing to one side leaving leadwires connected.
NOTE
Remove onl y one head-arm assembl y a t a
time.
As each head-arm assembly is
removed, observe order in which they are
removed and layout in order of removal.
Lay each head (face up). on a clean
surface. Each head-arm assembly must be
installed in the same slot from which it
was removed.

12.

Remove head-arm assemblies starting with head
to head-arm assembly replacement procedure
4.8, step 8).

13.

Remove read/write logic chassis as follows:
a.

R~move

Remr)ve four scr ews and washer s sec ur ing
logic chassis to deck and remove chassis.

0e.

Refer
(paragraph

connectors from cards,

4-7

read/wr i te

14.

Refer to velocity transducer assembly replacement
(paragraph 4.35, step 5), and remove velocity transducer
from magnet assembly.

15.

Remove magnet assembly as follows (refer to Figure 4-2):
a.

Loosen four screws secur ing rear deck seal to frame
and remove rear deck seal,

Loosen four screws secur ing deck rear plate to deck
and remove rear deck plate.
Reposi tion rear top
cover and hold down latch to either side,

Remove plastic magnet
magnet assembly.

cover

prying

cover

from

CAUTION

The screws removed in the next step go
through the actuator housing.
Thread
this into the aagnet assembly.
The
magnet will have a strong pullan the
wrench used to remove this screw so use
care not to damage actuator components.
d.

Remove scr~w securing actuator housing to magnet
ass em b 1 Y•
Th i s sc r e w is 10 cat e d at the to pin sid e
surface of the actuator housing next to the magnet.

Remove two screws secur ing
mo unt on magnet.

Move carriage as far forward as possible.

Remove three screws and washers (under deck) securing
magnet assembly to deck.

stop rod

plate

stop

CAUTION

When removing magnet assembly, use care
not to daaage voice coil. Also be sure
to place magnet away from metallic
objects.
h.
16.

Remove magnet from deck by sliding it straight back
from the voice coil.

Remove carriage and voice coil from actuator housing as
follows (refer to Figure 4-2):
a.

Remove nut and screw securing
bra c k e t a n d v 0 ice co i 1 flex
housing,

4-8

flex lead mounting
leads to actuator

b.
17.

Back carriage out of actuator housing, being careful
not to damage voice coil flex leads.

Remove seven screws and washers securing actuator housing
to deck. Then lift actuator housing straight up off pin
and deck.
NOTE
The defective actuator assembly has now
been completely removed. The following
steps describe Installation of the
replacement actuator assembly.

18.

Prepare replacement actuator for installation as follows:
a.

Remove nut and screw securing the flex lead
adj ustment bracket to actuator housing.
This frees
the flex leads and bracket from the housing.

Back carriage out of actuator housing, using care not
to damage voice coil flex leads.

Check to see that there are no burrs or foreign
particles on mounting surfaces of ·deck or actuator
housing. If necessary clean these surfaces.
NOTE
When installing actuator housing, leave
screws loose enough to perform carriage
tC) spi ndle al ignment.

19.

Install actuator housing on deck using seven screws and
washers.

20.

51 ide car r iag e into actua to r hous ing taki ng car e not to
damage voice coil flex leads.

21.

Align carriage to spindle as follows:
a.

Install and position carriage alignment arm as
iostr ucted in step 5 (8, b and c) of car r iage to
spindle alignment procedure (paragraph 4.32).

Check to see that clearance between carriage
a1 ignment arm and spindle post is between 0.002 and
0~004 inches (paragraph 4.32).

If requirements of step c (paragraph 4.32) are not
met, gently tap actuator on one side or the other to
move it in the proper direction.

4-9

NOTE
Do not disturb actuator posi tion when
removing carriage alignment arm and
carriage.
d.

Remove carriage alignment arm from carriage.

Remove carriage from actuato~ housing.
NOTE
Start wi th center screws when secur ing
actuator housing to deck and use care
not to disturb actuator position.

Torque the seven screws securing actuator housing to
deck to 60 <±5) inch-pounds.

Slide carriage into actuator housing.

Check to ensure alignment was not disturbed while
torquing actuator housing screws by repeating steps a
If requirements of step b are not met,
and b.
continue from step i. Otherwise proceed to step m.

Remove carrfage alignment arm.

Back carriage out of actuator housing.

Realign as instructed in steps a through h.

Remove carr iage. al ignment arm.

22.

Apply Loctite, grade C, to threads of screw and attach
va ice co i 1 flex lead mounting bracket to actuator
housing.

23.

Move carriage and check to see that voice coil flex leads
do not bind and ride approximately parallel to deck.
If necessary, adjust flex
these conditions are met.

lead mounting

bracket

until

CAUTION
While perforaing next step, use care not
to damage voice coil windings.
24.

Install magnet assembly as follows:
a.

Move carriage forward as far
unloading bearings from rails,

Carefully slide magnet into position and loosely
secure it to deck using three screws and washers.
4-11

possible

without

CAUTION

While performing the following step, use
caution not to da_age voice coil.
25.

Align magnet and voice coil as follows.
a.

Loosely install screw and washer
actuator into magnet assembly.

through

top

Move voice coil in and out of magnet assembly slowly.
Ensure that voice coil does not touch magnet
assembly.
Move magnet assembly, if necessary, to
avoid contact with the voice coil.

While

moving coil in and out of magnet, insert a
inch non-metallic feeler gauge between the coil
and magnet.
This ensures that an 0.005 inch gap
exists all around the coil.
0.~05

Torque the screw through the top of the actuator to
60 (.±2) inch-po unds.

Recheck gap (step c) and, if required, loosen screw
and repeat steps b through d until' proper gap is
obtained.

Torque three screws secur ing magnet
(:!: 1) inc h-po unds •

k gap (step c) and, if required, loosen all
magnet screws and repeat steps b through f until
proper gap is obtained.

deck

Rec~hec

26.

Secure stop rod plates to magnet assembly with two screws
and washer s.
Ensure that stop rods do not rub on stop
plates during carriage movement.

27.

Replace plastic magnet shield.

28.

Replace velocity transducer assembly (refer to paragraph
as follows:

-4.35)

Insert coil housing containing transducer
extension rod into rear of magnet.

Position end cap and sp'ring on magnet and then secure
with two screws and washers.

Apply one drop of Loctite, grade C, to extension rod
threads. Then thread extension rod into carriage and
tighten.

Connect velocity transducer cable plug P4.
4-11

core and

29.

Replace heads-loaded swi tch on actuator
two screws and washers.

housin9,

using

30.

Perform heads-loaded switch adjustment
(paragraph 4.11, steps 6 through 15).

31.

Position read/write chassis on deck and secure usin9 four
screws and washers.

32.

Replace cable connectors on read/write chassis cards.

procedure

NOTE

Inspect beads before installing them.
Refer to head inspection and cleaning
procedure, paragraph 4.7.1.
33.

Replace head-arm assemblies
follows.

(starting at bottom)

CAUTION

Ensure that head cable and plug do not
contact bead pad on adjacent heads or
they may be damaged.
a.
b.

Install head-arm, plug and cable carefully between
existing heads until head-arm is in proper position.
Install head-arm clamp screw and

torque

to 4 inch-

po unds.

If installing read/write head-arm, connect head cable
plug to SGN card in read/write chassis location E05.
If installing servo head, connect servo cable jumper
plug to connector card on actuator housing_

Repeat steps
installed.

through

for

all

heads

34.

Replace voice coil leadwire.

35.

Secure heads-loaded switch and voice coil lead wires to
side of actuator housing with cable ties.

36.

Replace servo preamp assembly as follows:
a.

Position servo preamp housing
using two screws,

Connect servo head plug to servo preamp board,

Secure cover to servo preamp housing using two screws
and washers.

4-12

deck

and

secure

37.

Position deck rear plate on deck and
four screws (refer to Figure 4-2).

securely tighten

38.

Position rear deck seal on frame and secure by tightening
four screws (refer to Figure 4-2).

39.

Replace shroud and shroud cover.

40.

Replace pack access cover.
NOTE
If the drive was moved from in-line
position to remove top cover, reinstall
drive in-line after replacing top cover.

41.

Replace cabinet top cover.
CAUTION
Before installing a disk pack, allow
blower to operate for at least two
minutes.
This is necessary to purge
shroud area of foreign particles that
may have accumulated during actuator
. replacement.

42.

Perform the procedures listed below.
a.

Head alignment (paragraph 3.17.2)

Servo system adjustment (paragraph 3.17.2.7)

4.3
BLOWER MOTOR REPLACEMENT
The blower motor is located within the blower assembly as shown in
Figure 4-3.
Replacing the motor requires removing the entire
blower assembly from the drive.
The following describes removal
and replacement of the blower motor.
1.

Remove power from dr ive as follows:
a.

Press START swi tch
heads,

stop dr ive motor

and

unload

motor)

from

b •. Set main AC circuit breaker to OFF.
2.

Remove disk pack.

Open cabinet front door.

Remove blower assembly (containing
drive as indicated below.
a.

blower

Remove protective plate from drive frame,

4-13

AIR OUTPUT
TO DISK AREA

ABSOLUTE
AIR FILTER
~~:..-----AIR
r¥~---AIR

OUTPUT TO LOGIC CHASSIS
OUTPUT TO POWER SUPPLY

BLOWER MOTOR

AIR INTAKE SECTION

Figure 4-3

9W38

Blower Assembly

Loosen clamp on large hose located on top of blower
enclosure, then slide clamp up on hose and remove
hose from blower enclosure,

Remove two screws
enclosure to deck,

securing

4-14

bottom

front

blower

From the rear of the dr i ve, remove the two small er
hoses from the blower enclosure.
Turn hoses in a
clockwise direction until they come free,
CAt.rrION

Hoses actually unscrew from their
position .in blower enclosure but use
care not to exert too much upward force
or hoses will tear.
e.

Disconnect blower motor cable
connector on blower enclosure,

plug

from

its

81 i.de blower enclosure out of front of dr ive and set
on floor.

Snap J9 out of its position on air intake section of
blower enclosure and allow it to hang from its leadwire.

Disconnect ground strap from
section of blower enclosure.

Remove four posts secur ing upper air output section and
absolute air filter and set aside.

Lift lower air 'output section containing blower motor off
the air .intake section.

Remove six screws and nuts securing blower motor to lower
air input section and remove motor.

10.

Position replacement blower motor on lower
section and secure with six screws anq nuts.

11.

Set lower air output section (with motor mounted) on air
intake section.

12.

Reconnect ground strap and install J9 in its position on
air intake section.

13.

Observing arrows indicating air flow,
filter on lower air output section.

14.

Secure upper air output section with four springs.

terminal

CAUTION

Replace blower enclosure in drive as follows:

4-15

air

intake

input

set absolute

Following replacement of blower assembly, the blower should be allowed to
purge system for at least two minutes
before installing a disk pack.
15.

air

Connect blower motor cable plug P9 to J9 on rear of
air intake section,

Connect small air hoses to rear of lower air output
section by screwing them counterclockwise into holes.
Refer to Figure 4-3 for proper orientation,
CAUTION
Ensure that air hoses or
cable are not pinched.

16.

blower

motor

Slide blower into drive until flange on rear lower
edge of blower enclosure slips into channel on
cabinet frame,

Secure front of blower
screws,

Slip large air hose over output hole on top of blower
enclosure and secure with clamp,

Replace protective plate on drive frame.

e~closure

to cabinet using two

Close cabinet front door.

4.4
DRIVE BELT REPLACEMENT
The dr i ve bel t (refer to Figure 4-1) transfer s dr ive moto r power
to the spindle.
It is removed by first removing the two idler
springs, which keep tension on the belt, then slipping it off the
pull e ys •
Wh en t he bel t i s rep 1 aced, the d r i ve bel t ten s ion ma y
need adj ustment (refer to drive belt adj ustment procedure,
paragraph 4.5).
The following describes removal and replacement
of the drive belt.
CAUTION
A drive belt should only be removed by
fir st remov ing the two tens ion spr i ng s
as directed in the replacement procedure.
Never remove a dr ive bel t by
rolling the belt off the pulleys or
damage to the drive motor shaft or belt
will result.
1.

Remove power to drive as follows:
a.

Press START
heads,

switch

Set MAIN AC circuit breaker to OFF.

Remove disk pack.

4-16

stop drive

motor

and

unload

Open cabinet rear door and swing logic chassis open.

Remove blower enclosure from dr ive cabinet.
Refer to
blower motor replacement procedure, paragraph 4.3, steps
3 and 4.

Remove static· groundspring leadwire from static groundspring.

Disconnect speed sensor cable plug A3P3.

Note lead wire connections
leadwires at pack on switch.

and

disconnect

pack

CAUTION

Use care not to damage the pack sensor
assembly when removing drive belt.
8.

Remove drive belt as follows (refer to Figure 4-4):
a.

Remove two idler springs.

Push dr i ve moto r toward spi ndle assembl y to rel i eve
tension on drive belt and then slip belt off pulleys
and set aside.
NOTE

Smooth surface of belt goes against
pulleys.
9.

Install replacement belt as follows:
a.

Position belt around drive motor pulley,

Push dr ive motor toward spindle and sl ip bel taro und
spindle pulley,

Install idler springs,

Move drive motor and mounting plate back and forth
several times to ensure the mounting plate is
properly seated,

Manually
pulleys.

rotate

spindle

align

drive

belt

10.

Connect speed sensor
leadwire.

11.

Connect pack on switch leadwires to switch terminals.

plug A3P3 and static groundspr ing

4-17

STATIC GROUNDSPRING

PACK ON SWITCH
PACK SENSOR ASSEMBLY

APPLICABLE TO VOE UNITS ONLY

BRAKE ASSEMBLY ~

CZ·0&45

Figure 4-4

Drive Belt Replacement/Adjustment

12.

Replace blower assembly.
Refer to blower
replacement procedure, paragraph 4.3, step 15.

13.

Close cabinet rear door.

14.

Perform drive belt adjustment procedure
starting with step 3.

motor

(paragraph 4.5)

4.5
DRIVE BELT ADJUSTMENT
The drive belt adjustment consists of changing the belt tension
which is maintained by the two idler springs. These springs are
attached between posts mounted on adjustable brackets on the deck
casting and fixed posts mounted on the motor mounting plate (refer
to Figure 4-4).
The drive motor mounting plate is moved by the
springs to exert tension on the belt. The springs are adjusted by
removing them from the brackets, repositioning the adjustable
brackets and then replacing the springs.
4-18

Remove power to drive as follows:
a.

Press START swi tch
heads,

stop dr ive motor

Set MAIN 1\C circuit breaker to OFF.

and

unload

Remove disk pack.

Open rear door of cabinet and swing logic chassis open.

Inspect dr ive belt for cracks or worn spots.
If
required, replace belt by performing drive belt
replacement procedure (paragraph 4.4) starting with step
4.

Check drive belt adjustment by measuring distance between
idler spring posts. Refer to Figure 4-4.
This distance should be from 5.25 to 5.50 inches (135.35139.50 millimeters).
If distance is not within these
limits" adjustment is required.
Refer to step 6.
If
distance is 'within these limits, no adjustment is
required. Refer to step 7.

Adjust idler spring
tension as follows:

tension,

which

fro mit 5

is also drive

belt

po s teo nne c ted

a•

Rem 0 v e i d 1 e r s p r i n g
adjustment bracket,

Loosen two
reposition

Tighten screws securing adjustment bracket,

Replace idler spring on its posts,

screws securing adjustment bracket and
the bracket to 5.25 to 5.50 inches
(135.35 - 139.50 millimeters).

NOTE
Tension
between
idler
springs
is
interacting; therefore when adjusting
one spring always recheck both springs.
e.
7.

Recheck spring distance requirements
procedure starting with step 5.

Close logic chassis and rear door of cabinet.

4-19

repeating

4.6
DRIVE MOTOR AND BRAKE REPLACEMENT
The replacement motor assembly includes the motor, pulley, and
cable with attached plug.
Replacing the drive motor assembly
involves removing the motor mounting plate with motor attached.
The old motor is then removed from the mounting plate and the
replacement motor is mounted in its place. This assembly is then
replaced in the drive cabinet.
If the dtive motor includes an externally mounted brake assembly,
it must be removed from the old motor and installed on the
replacement motor.
4.6.1 Drive Moto~ Replacement
1..

Remove power from the dr i ve as fo llows :
a.

Press START swi tch
heads,

stop dr ive mo tor

Set MAIN AC circuit breaker to OFF.

and

unload

NOTE
If drive is installed in-line with other
drives, it must be taken out of line to
remove side panels.
2..

Remove cabinet side panels.

Open cabinet rear door and swing logic·chassis open.
CAUTION
Use care not to damage pack sensor
assembly when removing drive belt.

Remove drive belt by performing drive belt replacement
procedure, (paragraph 4.4) steps 5 through 8.

Remove drive motor and motor
( ref e r to Fig u r e 4 - 5) :

mounting

plate as

follows

Disconnect drive motor cable plug AIP7 from rear of
power supply.
If the motor includes an externally
mounted brake, disconnect A1P9 and brake cable plug
A3P2 on the power supply,

Remove motor relay box.
CAUTION
Dr ive motor and mounting plate requi re
support frOID beneath (such as block of
wood on floor of cabinet) to prevent
them
from
being
dropped
during
installation.
4-20

DECK CASTING

(----'1
INSULATOR____.......

'fi~

SPACER _ _

~rI
,

WASHER - - I

~/~

SCREW /'

~ORIVE

TOP VIEW

MOTOR

~ NON-VOE ONLY

& VOE ONLY
CABLE
~R

GRIENTATION

BRAKE

&
lOJll

Figure 4-5

Drive Motor and Brake Replacement

4-21

Remove hardware securing drive motor to mounting plate
and remove the drive motor and pulley from plate and set
aside.
Remove the externally mounted brake (if so
equipped) using the brake replacement procedure, and
install it on the replacement motor.

Replace drive motor and motor mounting plate as follows:
a.

Orient replacement drive motor and pulley as shown in
Figure 4-5 and secure it to mounting plate,
CAUTION
Drive motor and mounting plate require
support from beneath (such as block of
wood on floor of cabinet) to prevent
them
from
being
dropped
during
installation.
NOTE
Apply one drop of Locti te, grade C, to
threads of each screw installed in step
b.
00 not overtighten screws or motor
mounting plate will not be free to move
between spacers.

Position motor mounting plate and drive motor as
shown in Figure 4-5 and secure with hardware removed
in step 5,

Check that the motor mounting plate is free to move
forward and backwards between motor spaces. If not,
loosen screws and retighten so that mounting plate is
free to move.

Replace drive belt as follows:
a.

Push drive motor toward spindle and slip drive belt
around drive motor pulley,

Install idler springs,

Move drive motor and mounting plate back and forth
several times to ensure the mounting plate is
properly seated,

Manually rotate
pulleys,

Connect speed sensor
spr ing leadwire,

Connect pack-on switch leadwires to switch terminals.

spindle

4-22

plug

align

A3P3

and

drive
static

belt

ground

Connect drive motor cable plug AlP7 to J7 and brake cable
A3P2 on rear of power supply_

10.

Replace motor relay box and connect AIP9 to J8 on rear of
power suppl y.

11.

Close logic chassis and then close cabinet rear door.
NOTE
If drive was moved from in-line position
prior to removing side panels, reinstall
drive in-line after replacing side
panels.

12.

Replace side panels.

4.6.2 Brake Replacement
The brake assembly, on units so equipped, is mounted on a bracket
attached to the bottom of the drive motor. The brake applies its
braking force to the motor through a flexible coupling connecting
the motor and brake shafts.

When replacing a drive ,motor, the brake assembly must be
transferred to the replacement motor. Use the following procedure
to transfer the assembly, or to replace the brake.
1.

Remove the drive motor using the drive motor replacement
procedure.
It is not necessary to remove the motor from
the mounting plate if the motor is not being replaced.

Remove the hardware securing the brake mounting bracket
to the bottom of the motor. See Figure. 4-5.

Separate the brake and bracket assembly from the motor.
NO'TE
If the brake is being transferred to a
replacement motor, go to step 4. If the
brake is being replaced, go to step 9. "

~}osen
the setscrews in the flexible coupling on the
motor shaft and slip the coupling off the motor shaft.

Install the coupling on the
tighten the setscrews.

Assemble the brake and bracket to the motor using the
hardware removed in step 2.
Ensure that the flexible
c()upling compo.nents engage properly.

4-23

replacement motor,

lightly

Slide the· flexible coupling on the motor shaft downward.
Ensure that all coupling components engage properly and
tighten all setscrews.

Skip steps 9-15 and install the drive motor using the
drive motor replacement procedure, beginning with step 8.

Loosen the setscrew that secures the flexible coupling to
the brake shaft.

10.

Slip the coupling off the brake shaft.

11.

Remove the screws that secure the brake to the mounting
bracket.

12.

Assemble the replacement brake to the mounting
using the hardware removed in step 11.

bracket

13.

Slip the flexible coupling onto the brake shaft.
the setscrews in the coupling loose.

Leave

14.

Posi tion the brake and bracket assembl y on the mota rand
secure it with the hardware removed in step 2.

15.

Raise the flexible coupling on the brake shaft so it
engages the coupl ing components.
Tighten all setscrews
securely.

16.

Connect brake cable A3P2 to J8 on power supply.

17.

Install the drive motor using the drive motor replacement
procedure beginning with step 8.

4.7
HEAD-ARM ASSEMBLIES
The following describes head inspection and gives criteria for
determining if a head-arm assembly should be replaced.
A
procedure for replacing one or more of the head-arm assemblies is
al so i ncl uded.

The heads should be inspected only for the reasons given below.
1.

A problem is traced to a specific head or heads; for
example, excessive data errors. Replace head or multiple
head-select.

Head to disk contact is suspected. This may be indicated
by an audible ping, scratching noise, or a burning odor
when the heads are over the disk area.

Concentric scratches are observed on the disk surfaces.

Contamination of pack is suspected
improper storage of the pack).
4-24

(possibly

due

The pack has been physically damaged
dropping or bumping).

(possibly due

CAUTION

Do not attempt to (Dperate the .edia on
another dr ive until full assurance is
made that· no damage or contamination has
occurred to the media.
Do not attempt to operate the drive with
another media until full assurance Is
made that no damage or contamination has
occurred to the dr ive beads or to the
shroud area.
Replace all heads in the
event of a head crash where there is a
large amount of particle contamination.
Examples of this are problems 2 and 3 of
4.7 f.
4.7.1

Head Inslpection
CAUTION

Do not smoke when inspecting heads. Use
extreme care not to damage the bead.
Do not touch the head pad or gimbal
spring with fingers or tools.

If head must be laid down, do not allow
the head pad or gimbal apr ing to touch
anything. If possible, use a magnifying
device to inspect the beads.
Remove suspect head as described in Paragraph 4.8.
Refer to
Figure 4-6, observe the head-arm assembly, and perform the remedy
given below.
1.

I f red dis h - b r 0 wn 0 x ide de po sit sex i s ton
replace the head-arm assembly.

If head appears scratched, replace the head-arm assembly.

If head appears damaged, replace the head-arm assembly.

If the gimbal spr ing which holds the head pad to the arm
is bent or damaged, replace the head-arm assembly.
CAUTION

not reuse any packs that were used on
these types of heads.

4-25

the

he ad,

FERRITE CORE

HEAD PAD
FLYING SURFACE
-------GIMBAL SPRING

9W41

Figure 4-6

Typical Head-Arm Components

4.7.2
Head-Arm Replacement Criteria
A head-arm assembly requires replacement if any of the following
conditions listed below sxist.
1.

Consistent oxide buildup on the
repeated head to disk contact

same head,

indicating

Appreciable oxide build-up

Scratches on the head flying surface

Imbedded particles in the head pad flying ·surface

Bent or damaged gimbal spring

Any apparent physical damage to head-arm assembly

4.8
READ-ARM ASSEMBLY REPLACEMENT
The following describes replacement of read/write and/or the servo
head-arm assembl ies.
Head al ignment must be per fo rmed on any
head-arm assembly replaced. Replacing the servo head-arm assembly
requi res al ignment of all heads. Head al ig nment is covered in a
separate procedure (paragraph 3.17.2).
NOTE

In the event of suspected contamination
of the shroud, the shroud should be
removed, cleaned and replaced in conjunction with this procedure. The
actuator assembly and deckplate must
also be cleaned.
4-26

Remove power from drive as follows:
B.

Press START switch
heads,

stop drive motor

Set MAIN AC circuit breaker to OFF.

and

unload

Open pack access cover, remove disk pack and then close
pack access cover.

Open cabinet top cover and remove deck cover.

Open pack access cover as far as possible.
NOTE
Perform step 5 if any of the items below
apply.
•

If removing all heads

•

If removing any of the heads
surface positions 15 through 19

If removing the servo head. In this
case, per form only a and b under
step 5.

If none of these apply, proceed to step
6.
5.

Move servo preamp housing as follows:
ao

Remove two screws
remove cover,

securing

cover

housing

Disconnect servo head cable plug
board,

Remove two screws securing preamp housing to deck,
then move preamp housing to provide access to head
clamp screws for head surface positions 15 through

from servo

and

preamp

19.

Determinfe sur face location of head (or heads to be
replaced) by referr ing to head identi fication label
on actuator housing or to Figure 4-7.

Lock carriage in place by inserting carriage locking pin
into shipping hole.

Remove heads as follows:

4-27

ADJUSTMENT
HOLES
CLAMP SCREWS

~
CJCJ~ I; W.,:7

\)o 0"11
<j'

CJ~:

<o~

~~\~ ~~
\) \)\1 ~ .

1\ ~

,.~

LEFT SIDE VIEW

RIGHT SIDE VIEW

9W43

Figure 4-7

Head-Arm Assembly Replacement

NOTE
If more than one head is to be removed,
disconnect head cables one at a time as
the heads are removed.
a.

If removing read/write head, disconnect corresponding
head cable plug from XGN card in read/write chassis
location ESS.
If removing servo head, disconnect
servo cable jumper plug from connector card on
actuator housing. ·

4-28

CAUTION
When head-arm clamping screw is removed,
use care not to dislodge bead from 1 ts
po sit ion inca r r i age.
Th is .ay a 110 w
head to contact an adjacent bead thus
causing damage to itself or other head.
If more than one bead Is to be removed,
undo clamping screws one at a time.

Remove clamping
removed.

screw

securing

head-arm

Cit

81 ide head-arm assembly forward. from its posi tion in
carriage until it can be grasped from front, then
carefully remove head-arm, cable and plug from
carriage assembly.
.

Repeat steps a through c for all heads to be removed.

Install heads as follows:
CAUTION

Ensure. that head plug and cable do not
. contact head pad on adjacent heads or
these heads may be damaged.

10.

Slide head-arm, plug and. cable carefully between
existing heads until head-arm is in proper position.

Install head-arm
inch-po unds,

If installing read/write head, connect head cable
plug to XGN card in read/write chassis location E05.
If installing servo head, connect servo cable jumper
plug to connector card on actuator housing,

Repeqt steps
installed.

clamp

through

screw

and

for

torque

all

heads

Remove carriage locking pin from shipping hole.
NOTE

Step 11 is applicable only if step 5 was
performed.
11.

Reinstall servo preamp housing as follows:
a•

Plac e i tin its pro pe r
with two screws,

Reconnect servo head cable plug to preamp board,

4-29

po sit ion

n dec k and sec u r e

Replace servo preamp housing cover using two screws.
NOTE
not adjust servo head-arm if it was
not replaced because all read/wr i te
heads must be realigned whenever this
adjustment is changed.
Do

12.

13.

If servo head-arm was replaced,
Otherwise, proceed to step 14.

adj ust

it as

follows.

Using head-arm adjustment tool, center servo head-arm
adjustment slot in the head adjustment hole,

Torque head-arm
inch-po unds.

clamp

screw

(.:!:

1/2)

Check alignment of all heads and adjust as necessary
(refer to head alignment procedure, paragraph 3.17.2).

4.9
HEAD CAM REPLACEMENT
This procedure describes removal and replacement of the head cams.
The top cover, pack access cover, shroud, and shroud cover must be
removed to gain access to the head cams. The cams fit onto pins
in the actuator housing and require no adjustment after
installation.
1.

Remove power from drive as follows:
a.

Press START switch
heads,

stop drive motor

Set MAIN AC circuit breaker to OFF.

and

unload

Remove disk pack.
NOTE
If drive is installed in line with other
drives, it may be necessary to move the
dr ive out of line to remove the top
cover.

Remove cabinet top cover.

Remove pack access cover.

Remove shroud and shroud cover.

Manually load heads.

Remove two screws securing each head cam to actuator
housing and then remove cams by pulling straight off from
pins on actuator housing. (Refer to Figure 4-8.)
4-38

HEAD CAMS

Figure 4-8

Head Cams

CAUTION
Before replacing head cams, ensur. that
mating surfaces of actuator housing and
cams are clean.
8.

9.
10.

Install replacement head cams as follows (refer to Figure
4-8):
a.

Fit replacement head cams over dowel pins on actuator
housing so they are flush against housing,

Install screws and torque to 4 <±.S) inch-pounds.

Manually unload heads.
Replace

shroud

and

shroud

washers~

11.

Replace pack access cover.

4-31

cover

with

nine

screws

and

NOTE
If it had been necessary to move dr ive
fro min -1 i n e po sit ion t o r em 0 veto p
cover, reinstall drive in-line after
replacing top cover.
12.

Replace cabinet top cover.

4.19 HEADS-LOADED SWITCH REPLACEMENT
This switch is mounted on the actuator housing (refer to Figure
4-9) and indicates to the drive logic whether or not the heads are
loaded.
The following describes the removal and replacement of
this switch.
This switch also requires adjustment which is
explained in the heads-loaded switch adjustment procedure
(paragraph 4.11).
1.

Remove power to drive as follows:
a.

Press START swi tch
heads',

stop dr ive

Set MAIN AC circuit breaker to OFF.

mo tor

Remove disk pack.

Open cabinet top 'cover and remove deck cover.

Move carriage back to retracted stop.

Remove head s-loaded swi tch from
follows (refer to Figure 4-9):

ac tua to r

and

unload

ho us i ng

Cut cable tie secur ing heads-loaded swl tch leadwi r es
to actuator housing,

Remove
two
sc r ews
and
washe r s
sec ur i ng
the
heads-loaded switch mounting block to actuator
housing, then remove mounting block and swl tch from
actuator housing,

No te leadwi re
swi tch,

Remove two screws and washer s
block and remove switch.

connec t ions

and

remove

leadwi r e

sec ur Ing

swi tch

from
to

Install replacement switch on mounting block.

Install replacement switch and mounting block on actuator
housing,
leaving screws loose enough to
perform
adjustments in step 8 of adjustment procedure.

Secure leadwires to side of actuator housing with cable
tie.
4-32

MOUNTING

,~
ACTUATOR HOUSING

9W45

Figure 4-9
9.
4.11

Heads-Loaded Switch Replacement

Perform
heads-loaded
swi tch adj ustment
( pa rag r a ph 4. 11 ) s tar t i ng wit h s t e p 6.

procedure

HEADS-LOADED SWITCH ADJUSTMENT

The heads-loaded switch should actuate when the carriage is
forward enough 1:or the heads to be loaded.
To ensure this
condition,' adjust the heads-loaded switch using the following
procedure.
1.

Remove power from drive as follows:
a..

Press START swi tch
heads,

stop dr ive motor

Set MAIN AC circuit breaker to OFF.

Remove disk pack.

Open cab i net top cover and remove dec k cover.
4-33

and

unload

Move carriage back to ratracted stop.

Note heads-loaded switch
disconnect leadwires.

Connect an ohmmeter (set to Rxl scale) across common and
normally closed (NC) terminals of the switch.
Refer to
Figure 4-9.

Check heads-loaded switch operation.

leadwire

connection

and

With carriage at retracted stop, meter should read
zero.
If it does not, proceed to step 8.
If it
does, proceed to b.

Move carriage forward until switch transfers (meter
indicates infinity) and measure distance traveled.
If distance is between 0.1 and 0.2 inches,proceed to
step 17.
If distance is not between these limits,
proceed to step 8.

Loosen screws securing switch mounting block to actuator
housing and then move block to actuator housing.
Move
block and switch as far back as possible toward magnet.
Meter should now indicate infinity.

Disconnect one of the meter leads at meter.
NOTE
In next step, a suitable shim is constructed by taping a number of feeler
gauges together until their combined
thickness is from 9.1 to 9.18 inches.
Check their thickness with a steel rul~.

10,.

Insert 0.15 (0.05) inch shim between stop on magnet and
shock stop on carriage assembly. Refer to Figure 4-10.

11.

Reconnect meter lead and note that meter still indicates
infinity when carriage is moved back against shim.

12.

Hold carriage against shim and then move heads-loaded
switch towards spindle until switch transfer occurs
(meter indicates zero).
Tighten screws securing switch
and mounting block to actuator housing, taking care not
to disturb their position.

13.

Remove shim and move carriage back to retracted stop.

14.

Move carriage forward and check with shim or steel rule
to ensure swi tch transfer occurs between 0.1 and 0.2
inches of retracted stop.

4-34

CARRIAGE
SHOCK STOP
MAGNET

CARRIAGE

SHIM

-' lOols (

0005) INCHES

9W46

Fi(3Ure 4-10

Heads-Loaded Swi tch Adj ustment

15.

If requirements of step 14 are not met ,. repeat steps 7
through 14 until the adjustment is correct and then
proceed to step 16.

16.

Disconnect meter from switch
heads-loaded switch leadwires.

17.

Replace deck cover and close top cover.

terminals

and

reconnect

4.12 LOGIC CHASSIS BACKPANEL REPAIR
Backpanel repair is limited to replacing damaged wires and bent or
broken pins. Both procedures are described below.
4.12.1 Wirewrap Pin Replacement
This procedure describes removing a damaged pin from the backpanel
and replacing it with a new one.
1.

Remove lx>wer from drive as follows:
a.

Pres;s START swi tch
heaels,

Set MAIN AC circuit breaker to OFF.

4-35

stop dr ive motor

and

unload

NOTE

Use care not to damage wires when
removing the. fro. pin. Also note level
of wires so they are replaced in the
same position as they were removed.
2.

Open cabinet rear
chassis card cage.

Remove all wires from pin. Refer to wirewrap replacement
procedure, paragraph 4.12.2, step 3.
Remove card associated with pin to be replaced.

door

and

remove

cover

from

log ic

Sl ide post removal tool over pin and apply pressure
toward backpanel until bond breaks between pin and collar
(refer to Figure 4~11).

G sp shank of pin (with long nose pliers or similar
tool) and pull it out of backpanel. If collar comes out
wi th pin, proceed to step 7. If collar remains secure In
backpanel, proceed to step 8.

Coat collar of replacement pin (not hole) with epoxy and
insert it into backpanel from wirewrap side. Proceed to
step 9.

Insert replacement pin with collar removed from wirewrap
side of backpanel. Push it into collar in backpanel hole
until it is same length as adjacent pins.
CAUTION

Any cement on shaft of pin will prevent
an electrical connection.
9.

Apply fast cure epoxy cement around pin on wirewrap side
of backpanel to ensure tightness of pin. Refer to Figure
4-11.

10.

Replace wires removed in step 3.
Refer to wirewrap
replacement procedure, paragraph 4.12, steps 5 through 9.

11.

Replace cover on
cabinet rear door.

logic

4.12.2 Wirewrap Replacement
This procedure describes removal
wirewrap connections.
1.

chassis

and

card

cage

replacement

and

backpanel

Remove power from drive as follows:
a.

Press START switch to
heads,
4-36

stop drive motor

and

unload

COLLAR

WIREWRA~~
PIN
9W47

Figure 4-11
b.
2.

Wirewrap Pin Replacement

Set MAIN AC circuit breaker to OFF.

Open cabinet rear door.
NOTE
If pin has two wi res and the wire to be
replaced is closest the to backpanel, it
is necessary to remove the other wi re •
In this case, use care not to damage the
other wire.
"

To unwrap each end of wire, use end of wirewrap tool with
notch opposing direction of wrap and slide tool over pin.
Carefully turn tool to unwrap wire.

Cut replacement wire to proper length and strip approximately 1 1/8 inch of insulation from each end of wire.

Insert one end of wire into
insulation rests against stop.

Slide tool over backpanel pin leaving a small gap between
bottom of post or lower wrap level and new wire.

Ho 1d wi res ec u r ely ( a 110 w a sm a 11 amo un t 0 f slack to
assure one turn of insulation) and twist tool to wrap
wire aro·und pin.
As tool is twisted, wire wrapping
around pin forces tool up and off wire.

4-37

wirewrap

tool

until

When wire is completely wrapped, remove tool and proceed
to wrap other end of wire to its pin.

Ensure that each connection has one turn of insulation
and six to seven turns of bare wire around pin.

1~.

Close cabinet rear

doo~.

4.13 OPERATOR CONTROL PANEL REPLACEMENT
The operator control panel 1s replaced by snapping it out of the
shroud cover, removing it from the connector and replacing it with
a new control panel assembly.
1.

Remove power from drive as follows:
a.

Press START swi tch
heads,

stop dr ive mo tor

Set MAIN AC circuit breaker to OFF.

Open pack access cover and remove disk pack.

Open cabinet top cover.

Remove plastic plug from
Refer to Figure 4-12.

access

hole

and

unload

shroud

cover

NOTES:

TOP COVER MUST
BE OPEN TO REMOVE
CONTROL PANEL

Figure 4-12

9W48

Operator Control Panel Replacement

Snap operator control panel out of its position in shroud
cover. Refer to Figure 4-12.

Remove control panel cable plug P201
assembly card and set assembly aside.

4-38

from

control

Install control panel connector plug P20l on replacement
operator control panel and then snap replacement control
panel into its position in shroud cover.

Close pack access cover.

4.14

PACK ACCESS COVER SOLENOID REPLACEMENT (NON-VDE)

This solenoid is mounted on the front of the shroud cover and
prevents the pack access cover from being opened whi Ie the spi ndle
is turning.
Refer to Figure 4-13.
The following descr ibes
replacement.
Adjustment is covered in the pack access cover
solenoid adjustment procedure (paragraph 4.15).
1.

Remove power from drive as follows:
a.

Press START switch
heads,

stop drive motor

Set MAIN AC circuit breaker to OFF.

and

unload

Remove disk pack.
NOTE

If drive is installed in-line with other
drives, it will be necessary to pull
drive out of line to remove top cover.
3.

Remove cabinet top cover.

Remove pack access cover.

Snap operator control panel out of its position in shroud
cover and let it hang by control panel· cable wires.

Remove 12 screws securing shroud cover to shroud and move
shroud cover forward far enough to allow access to pack
access cover solenoid assembly.

Remove two screws and washers securing solenoid assembly
and slip it out from beneath shroud cover.

Note solenoid leadwire connections, disconnect leadwires
and set solenoid aside.

Install replacement solenoid to shroud cover
screws and washers.

l~.

Connect leadwires to solenoid.

11.

Move shroud cover back into position and secure using 12
screws.

4-39

using

two

~""f

=-~ SHROUD COVER'

COVER CATCH

& 0.12 INCHE~

::!~--

~ SOLENOID LATCH
SCREW SECURING CATCH

SOLENOID ASSEMBLY

,'.---_

~I~·

LOCSK~~ESWHER~

: r - '- - - '

FLAT WASHER

~~H (ATTACHED TO SHROUO COVER)

COVE~~~\

PACK ACCESS
(ATTACHED TO PACK ACCESS '\
COVER)
SOLENOID LATCH
SHOWN IN
NOTES:
ENERGIZED POSITION

~ SHOWN IN ENERGIZED POSITION

& ACCESS
NOT CRITICAL. HOWEVER DISTANCE MUST ENSURE PACK
COVER Will BE lOCKED SHUT BY SOLENOID LATCH
9W49

Figure 4-13

Pack Access Cover Solenoid
Replacement/Adjustment (NON-VDE)

12.

Replace pack access cover.

13.

Replace operator control panel in shroud cover.

4-41

NOTE
If it vas necessary to move drive from
In·-line position to remove top cover,
reinstall drive in-line after replacing
top cover.
14.

Replace cabinet top cover.

15.

Perform pack access cover solenoid adjustment procedure
(paragraph 4.15).

4.15 PACK ACCESS COVER SOLENOID ADJUSTMENT (NON-VDE)
This adjustment consists of moving the solenoid assembly (installed on the shroud cover) up or down until the clearance
between it and the cover catch is correct. When this is accomp1 ished, the sol'enoid should prevent the cover from opening when
the spindle is turning.
1.

Remove power from drive as follows:
a.

Press START swi tch
heads,

stop dr ive motor

Set MAIN AC circuit breaker to OFF.

and

unload

Remove disk pack.

3•

Ra i sec a bin e t to p co v e r •

Raise pack access cover as far as possible.

Check adjustment by pushing solenoid latch up to simulate
energized condition and then measure .distance between it
and catch on shroud cover ~ Refer to Figure 4-13.

If distance measured in step 5 is as indicated on Figure
4-13, proceed to step 7. Otherwise, adjust as follows:
a.

Loosen
cover,

screws securing

solenoid assembly

shroud

b•

Ho 1d so 1 e no i d 1ate h in en erg i ze d po 5 i t ion an dad jus t
solenoid assembly until proper clearance is obtained,

c•
7.

Ti g h ten sc r ews sec ur i n9 so 1 eno i d assembl y to sh r 0 ud
cover.
Perform final check as follows:

Close top cover all,owing pack access cover to fully
open,

Install
cover,

scratch

disk

4-41

pack

and

pack

access

Set MAIN AC circuit breaker to ON,

Press START
heads,

Solenoid should energize and prevent pack access
cover from being opened.
If it operates properly,
proceed to step 8.
However if cover can be opened,
repeat steps 1 through 6.
Also check catch, latch,
and solenoid for proper operation.

swi tch

start

dr ive

mo tor

and

load

Remove disk pack.

Press START switch to stop drive motor and unload heads.

19.

Set MAIN AC circuit breaker to OFF.

11.

Close pack access cover.

4.16 PACK ACCESS COVER SWITCH REPLACEMENT (NON-VDE)
This switch prevents the drive motor from starting when the pack
access cover is open.
It is located under the shroud cover as
shown in Figure 4-14.
The following describes its removal and
replacement. This switch cannot be adjusted.

SHROUD
COVER

PACK
ACCESS
COVER

~~~F

SWITCH

MOUNTING
BRACKET
9WSO

Figure 4-14
1.

Pack Access Cover Switch Replacement (NON-VDE)

Remove power from drive as follows:
a.

Press START swi tch
heads,

Set MAIN AC circuit breaker to OFF.

4-42

stop dr ive motor

and

unload

Remove disk pack.

Open cabinet top cover and remove deck cover.

Open pack access cover as far as possible.

Open pack ac·cess cover swi tch assembly as shown below.
Refer to Figure 4-14.
a.
b.
c.

Remove two screws and washers secur ing pack access
cover switch assembly to shroud cover and remove
switch assembly from beneath shroud cover.
Note leadwire connections and remove leadwires from
swi tch.
Remove two screws and washers securing switch to its
mounting bracket and then remove switch from bracket
and set aside.

Replace pack access cover switch assembly as follows:
B.

Position replacement switch on mounting bracket and
secure using ·two screws and washers,

Connect leadwires to switch terminals,

Po si t ion swi tch under shro ud cover
two screws and washers.

and

sec ur e wi th

Close pack access cover.

Replace deck cover and close cabinet top cover.

4.17 INTERLOCK SOLENOID AND SWITCH REPLACEMENT (VDE)
The interlock assembly shown in Figure 4-1S is used on VDE units.
Its purpose is to lock the pack access cover so it can only be
opened when the drive is in the standby mode (MAlN AC breaker on
and drive motor stopped).
It also prevents the drive motor from
starting if the pack access cover is open.
The fo11owi ng procedure deta i 1 s
interlock assembly.

removal

and

replacement of

Press the START switch to stop the drive.

Open the pack access,
remove the disk pack.

Remove the cabinet top cover.

Remove the pack access cover.

the

turn off the MAIN AC breaker and

4-43

SOLENOID~-------_..J

t='\

SHROUD ASSEMBLY

lOJ12

Figure 4-15

Interlock Assembly (VDE)

Remove the shroud cover attaching hardware and slide the
cover forward far enough to allow access to the interlock
assembly.

Disconnect interlock connector A3P9.
4-44

Note thE~
them.

lead

position on the solenoid and disconnect

Remove the hardware securlngthe interlock assembly to
the shroud. Slip the assembly out of the drive.
•

If the solenoid is being replaced, proceed with step
9.

•

If the interlock switch is being replaced, go to step
14.

•

If the entire interlock assembly is being replaced,
reverse steps 1-8 to install the new assembly.

Remove the
br ac ket •

10.

Remove the solenoid and plunger.

11.

Install the solenoid plunger and solenoid on the bracket
and secure it with the hardware removed in step 9.

12.

Manually operate the solenoid and check for freedom of
. movement.
The solenoid body can be repositioned within
limits of the attaching hardware to eliminate slight
binding.

13.

Reverse steps 1-8 to install the interlock assembly.

14.

Note lead position on the interlock switch and disconnect
them.

15.

Remove the hardware that secures the

16.

hardware

that

secures

the

solenoid

s~itch

the

to the latch.

Install the new swi tch wi th the hardware removed in step
15.

17.

Attach the leads to the switch.

18.

Reverse steps 1-8 to install the interlock assembly.

With the interlock assembly installed, the pack access cover
should lock when the drive motor is running, or when the MAIN AC
breaker is off.
NOTE
The interlock solenoid will not release
the latch (energize) for 30 seconds
after the MAIN AC breaker is turned on.

4-45

4.18

PACK-ON SWITCH REPLACEMENT

This switch is located on the pack sensor assembly. The following
descr ibes replacement of the pack-on swl tch.
The swi tch must be
adj usted following replacement, and this is covered in the pack-on
switch adjustment procedure (paragraph 4.19).
1.

Press START switch to stop drive motor and unload heads.

Open pack access cover and remove pack, close cover, and
set MAIN AC circuit breaker to OFF.
Remove blower assembly.
Refer
to blower motor
replacement procedure, paragraph 4.3, steps 3 and 4.

3.
4.

Note leadwire connections
pack-on switch terminals.

Remove hardware secur ing swi tch to swi tch base.

Install replacement swi tch to swi tch base us ing hardware
removed in step 5. Co not tighten screws.

Perform
4.19).

pack-on switch

and

disconenct

adjustment

leadwires

procedure

4.19
PACK-ON SWITCH ADJUSTMENT
"The pack-on swi tch must be adj usted to close
installed and open when the pack is removed.

(paragraph

when

pack

Refer to Figure 4-16 and proceed with the following steps.
SWITCH
BASE

PACK-ON
SWITCH

PACK-ON
SWITCH
.__'....__<:~--t---'iI ADJUSTMENT
SCREWS
GROUNDSPRING
TERMINAL LUG
AND ADJUSTMENT
SCREW
ACTUATOR
ARM

Figure 4-16

CZ·o:M

Pack-On Switch Replacement/Adjustment
4-46

Press START switch to stop drive motor and unload heads.

Open pack access cover.
a.

Remove disk pack.

Install scratch pack.

Clc)se cover.

Set MAIN AC circuit breaker to OFF.

Remove blower assembly. Refer to blower motor replacement
procedure, paragraph 4.3, steps 3 ~nd 4).

Note leadwire connections
pack-on switch terminals.

Using feeler gauge, measure distance between lockshaft
and actuator arm. If dimension is as specified in Figure
4-17, proceed to step 7.

and

disconnect

leadwires

~ SPINDLE

(~r-

~~~......-;-;::-~V

BELT

SPEED
SENSOR

STATIC
GROUND·
SPRING
PACK
SENSOR
ASSEMBLY
CZ·04OQ

Figure 4-17
6•

Pack Sensor Assembly Replacement

Lo 0 sen s wit c h bas e ad jus t men t sc r e wsan d rep 0 sit ion
swi tch base so that dimens ion between act ua tor arm and
lockshaft is as specified in Figure 4-16.

4-47

Check, and if necessary, adjust pack-on switch.
a•

P1 ace t est 1 ea d s 0 f
terminals of switch.

mu 1 tim e t e r

If meter indicates zero ohms, proceed to step 7e.
meter does not indicate zero, proceed to step 7c.

Loosen switch adjustment
indicates zero.

Tighten switch adjustment screws.

Insert a.0ll inch thick feeler gauge between actuator
arm and stop pin.

Multimeter must indicate infinity.
If not, go to
step 7g.
If cor rect, remove feeler gauge and go to
step 8.

Loosen pack sensor switch adjustment screws and
position switch until multimeter just indicates
infinity. Tighten screws.

Remove feeler gauge.
Multimeter must indicate zero
ohms.
If correct, go to step 8.
If not, repeat
procedure starting at step 7c.

screws

( se t a t

until

Rx 1 )

meter

If
just

Disconnect multimeter from switch terminals.

Connect pack sensor switch leadwires to switch terminals.

10.

Perform
static
groundspring
adjustment
procedure
(paragraph 4.34) if mounting plate screws· were loosened.

11.

Install blower assembly.
Refer to blower
replacement procedure, paragraph 4.3, step 15.

motor

4.20
PACK SENSOR ASSEMBLY RBPLACEMENT
This assembly is mounted beneath the deck on the rear of the
spindle.
The two main el~ments of the pack sensor assembly are
the static groundspring and pack-on switch.
The procedure for
individually replacing each of these are contained elsewhere in
this section.
The following describes replacement of the entire
pack sensor assembly. Refer to Figure 4-17.

Press START to stop drive motor and unload heads.

Open pack access cover and remove pack.
open, set MAIN AC circuit breaker to OFF.

Remove blower assembly.
Refer
to
blower motor
replacement procedure, paragraph 4.2, steps 3 and 4.
4-48

Leaving cover

Remove pack sensor assembly as follows:
a.

Disconnect static groundspring leadwire from terminal
on groundspring,

Cut tie wrap on leadwires,

NotE~

Disconnect speed sensor cable plug (A3P3),

Remove dr i ve bel t.
Refer to dr i ve bel t
procedure, paragraph 4.4,

Remove hardware securing pack sensor assembly to
spi odIe assembly, then remove pack sensor assembl y
and set aside.

leadwire connections
from pack-on switch,

and

disconnect

leadwires

repl acemen t

Install replacement pack sensor assembly as follows:
a.

Position replacement pack sensor assembly on rear of
spindle assembly and secure,

Replace drive belt.
Refer to drive belt replacement
procedure, paragraph 4.4,

Connect speed sensor cable plug (A3P3),

Connect leadwire to
groundspring leadwire.

pack-on

Perform the procedures listed below

switch

and

(p~ragraph

4.17).

Pack-on switch adjustment (paragraph 4.19)

Static groundspring adjustment (paragraph 4.34)

Speed sensor adjustment (paragraph 4.29)

Install blower assembly.
Refer to blower
replacement procedure, paragraph 4.3, step 15.

Perform
3.21.2.

speed

sensor

output check procedure,

static

motor

paragraph

4.21
PARKING BRAKE REPLACEMENT
The parking brake is located o~ the deck near the spindle. Refer
to Fig ur e 4-1B).
It is necessary to remove only the brake cover
pI ate to access the par ki ng brake fo r removal and repl acemen t •
Adjustment is covered in the parking brake adjustment procedure,
paragraph 4.21.

4-49

ACTUATOR BUTTON
ADJUSTMENT HOLE

BRAKE TOOTH
ADJUSTMENT
SCREW

LOCKNUT

ACUTATOR
BUTTON

LOC KNUT

BRAKE
PLATE

SCREWS SECURING
BRAKE TO DECK

Figure 4-18
1.

BRAKE
TOOTH

Parking Brake Replacement/Adj ustment

Remove power from drive as follows:
a.

Press START switch
heads,

stop drive motor

Set MAIN AC circuit breaker to OFF.

and

unload

Open pack access cover and remove disk pack.

Remove six screws and washers secur Ing brake plate cover
to deck and then remove cover.

Remove two screws securing parking brake assembly to
deck.
Refer to Figure 4-18 and then remove assembly and
set aside.
NOTE
Apply Loctlte prl.ar 9rade Nand Loctlte
grade C to screws used in step S.

Install parkln9 brake assembly to deck using two screws.

Perform parkin9 brake adjustment
4.22) startin9 with step 4.
4-S8

procedure

(paragraph

4.22
PARKING RAKE ADJUSTMENT
The parking brake has two adj ustments.
Refer to Figure
These are the actuator button to pack clearance and the
tooth to bottom of spindle clearance.

4-18.

brake

The distance between the actuator button and the disk pack bottom
disk surface is adjustea by turning the actuator button in or out.
The brake tooth to bottom of spindle clearance is adjusted by the
brake tooth adjustment screw.
Adjustment of brake tooth to bottom of spindle clearance requires
removing only the brake cover plate.
However, the entire shroud
must also be removed to adj ust brake button to disk pack
clearance.
1.

Remove

po~er

to drive as follows:

Press START
heads,

swi tch

stop dr ive

Set MAIN AC circuit breaker to OFF.

motor

and

unload

Open pack access cover and remove disk pack.

Remove six screws and washers secur ing brake cover plate.

Check clearance between
spindle as follows:

brake

tooth

and

Rotate spindle until brake
under a notch in spindle,

tooth

is not

Check to see if clearance between t~oth and underside
of spindle is between 0.005 and 0.020 inches.
If
thi s requi rement is not met, proceed to step 5.
If
it is met proceed, to step 6.

Adjust brake
follows:

tooth to

underside
engaged

of
or

underside of spindle clearance as

Loosen locknut brake tooth adjustment screw.

Adjust screw until clearance between tooth and
underside of spindle is from 0.905 to 0.020 inch.
Turning setscrew clockwise narrows gap and counterclockwise widens gap.

When gap is correct, tighten setscrew.

Install a scratch disk pack.

4-51

NOTE
In step 7, it is impossible to check the
clearance with a conventional feeler
gauge. However, a suitable tool can be
constructed by taping the proper feeler
gauge to the end of a long object such
as a screwdriver.
7.

Check that clearance between actuator button and bottom
disk surface on disk pack is between 0.01 and 0.02
inches. If the requirement is not met, remove disk pack
and proceed to step 8.
If it is met, remove disk pack,
replace brake cover plate and proceed to step 19.

Remove disk pack.
NOTE
If drive is installed in-line with other
drives, it may be necessary to move the
drive out of l1ne to remove the top
cover.

Remove cabinet top cover.

10.

Remove deck cover.

11.

Remove pack access cover.

12.

Remove shroud and shroud cover.

13.

Adjust actuator button to disk pack clearance as follows:
a.

Install scratch disk pack,

Loosen locknut on actuator button adjustment screw,

Turn actuator button until clearance between button
is between 0.10 and 0.02 inches.
Turning button
clockwise increases clearance and turning it counterclockwise decreases clearance,

When gap is correct, tighten locknut,
CAtn'ION

Remove and install disk pack and then
rotate spindle to ensure there is no
interference between brake tooth and
spindle.
e.
14.

Remove scratch disk pack.

Replace shroud, shroud cover and brake cover plate.

4-52

15.

Install pack access cover.

16.

Replace deck cover.
NOTE
If drive was moved fro. in-line position
to remove. top cover, reinstall drive inline after replacing top cover.

17.

Install cabinet top cover.

18.

Open pack access cover and clean shroud.

19.

Close pack access cover.

4.23 POWER SUPPLY ASSEMBLY REPLACEMENT AND MAINTENANCE
The power supply is located on the floor at the rear of the
cabinet.
Two types of power supplies are used.
These are
illustrated in Figure 4-19. One power supply is mounted on slides
tha t perm its ex tend ing it out the rear of the cabinet. The othe r
power supply is mounted on the base of the rear cabinet and does
not incorporat4~ the slides.
Both power supplies contain
replaceable cards. Table 4-1 shows card usage.

Table 4-1
Ca rd 'I'ype
VDE

Power Supply Card Usage
Card Type
NON-VDE

Description
Power amplifier
Relay board
Capacitor board
Recitifier/filter
board
Control board

ZCN
'-FNN
CBN
CFN

The following procedure describes replacement of the entire power
supply as well as each of the cards.
It also describes triac and
power transistor replacement.
4.23.1 Po.wer Supply Assembly Replacement (NON-VDE)
The following procedure describes removal and replacement of the
entire power" supply assembly.

Remove power from dr i ve as follows:
a.

Press START swi tch
heads,

Set MAIN AC circuit breaker to OFF,

Disconnect power cable from site power receptacle.

4-53

stop dr ive motor

and

unload

.i
I'

SUPPORT SPRING

/' :!

~~~
'\ /'1

LOGIC CHASSIS

·~i:
..,..:!

-' '/"

I '

/" ,..A"'.'. t~ - /~~
/<~ i
~ POWER CORD

/1.-'

I NON-VDE I

~/}

~,«~~
.

.......

POWER SUPPLY
SLIDES

lOJ13

Figure 4-19

Power Supply Assembly Location
NOT!

If drive is installed in-line with other
drives it will have to be pulled out of
line to remove side panels.
2.

Remove cabinet side panel s.
4-54

Remove two screws securing
remove cable guide.

Disconnect support spring from power cable.

Disconnect five plug connectors to power supply.
Also
disconnect ai·r hose by turning it in a co unter clockwi se
direction until it comes free.

Open cabinet rear door and swing logic chassis open.

Remove power supply top cover.

Disconnect ac and de ground straps and remove them from
power supply.
Refer to Figure 4-20.
Replace top cover
on power supply.

Remove six screws securing power supply slides to floor
of drive cabinet and slide supply out rear of cabinet.

10.

Slide replacement power supply into cabinet and
slides to floor of cabinet with six screws.

11.

Remove top cover from replacemen t po we r s uppl y and
connect ground straps (removed in step 8) as shown in
Figure 4-20.

12.

Connect power wiring as described in Chapter 2.

13.

Replace top cover on power supply.

14.

Reconnect five plugs to power supply. Also reconnect air
hose by screwing it cloc~wise into hole.

15•

Po sit i 0 In po we rca b l e i n cab l e g u ide
guide to floor of cabinet.

16.

Replace cabinet side panels.

17.

Connect power cord to site power receptacle.

18.

If drive was moved out
reinstall it in-line.

19.

Perform the procedures listed below.
and -5 volt

cable

line

guide

and

se cur e

perform

+5 volt
3.17.1)

test and adjustment

DC voltage output check (paragraph 3.18.1)

4-55

frame

and

secure

cab 1 e

step

(paragraph

I ~N· VDE POWER SUPPLY I

I vaE POWER SUPPLY I
IOJ14

Figure 4-20

Power Supply Card Replacement

4-56

4.23.2 -zeN (Power Amplifier) Card Replace.ent (NON-VDE)
The following procedure describes removal and replacement of only
the -ZCN card. Refer to Figure 4-19.
1.

Remove power from drive as follows:
a.

Press START swi tch to
heads,

stop drive motor

and

unload

Set MAIN AC circuit breaker to OFF,

Disconnect
tacle.

power cable from site main power

recep-

Slide power supply out and remove power supply top cover.

Note connections,
card.

Remove two screws and washers securing card in power
supply, remove insulated spring clip, then remove card.

S•

Po sit ion rep lac em en t car din po we r sup ply, a t t a c h
. insulated spring clip removed from old card (step 4), and
sec ur e ~7i th two· sc r ews and washer s.

Connect wires to replacement -ZCN card.

"'I.

Replace top cover on power supply and perform steps 1, 4
and 9 of manually controlled servo· checks procedure
(paragraph 3.18.2.2).

then disconnect

all

wires

from -zeN

4.23.3 -YEN (Capacitor Board) Replacement (NON-VDE)
The following prc:)cedure describes removal and ·replacement of the
-YEN card. Refer to Figure 4-20.
1.

Remove power from drive as follows:
a ..

Press START switch to
heads,

bO..

Set MAIN AC circuit breaker to OFF,

Disconnect
receptacle.

power

stop drive motor

cable

from

site

and

unload

main

power

Slide power supply out and remove power supply top cover.

Remove two screws and washers secur ing -ZCN card, remove
insulated spring clip, then move -zeN card away from
-YEN.

No te conn~ct ions,
card.

then

disconnec t

all

wi r es

from

-YEN

5t1

Remove ten screws securing card to capacitors.

Remove nut and washers from stud securing card to power
supply, then remove card.

Ensure that all lockwashers are positioned on capacitors,
then position -YEN card on capacitors and install ten
screws. Reconnect all wires to -YEN card.

Install nut and washers on stud and tighten nut.

Reposi tion -ZCN card and secure wi th two screws and
washers.
Replace insulated spring clip and all wires to
-ZCN card.

10.

Replace top cover on power supply and perform following
proced ures:
a.

+5 volt and -5 volt Test

and Adjustment

(paragraph

Voltage

(paragraph

3.17.1).

Power

Supply DC

Output

Check

3.18.1).

4.23.4 -YFN (Relay Board) Replacement (NON-VDE)
The following procedure describes removal and replacement of the
-YFN card. Refer to Figure 4-2".

Remove power from drive as follows:
a.

Press START switch
heads,

Set MAIN AC circuit breaker to OFF,

Disconnect
receptacle.

power

stop drive motor

cable

from

site

and

unload

main

power

51 ide power .supply out and remove power supply top cover.

Remove two connectors from -YFN card.

4..

Carefully pry card off three
power supply.

Install replacement -YFN card in power supply by pushing
it carefully onto fasteners.

Install two connectors on replacement card.

4-58

fasteners and

remove

from

Replace top cover on power supply, return power supply to
normal position, and perform the procedures listed below.
a.

Reconnect power cable to site main power receptacle.

Set MAIN AC circuit breaker to ON and set LOCAL/
REMOTE switch to LOCAL. Install a scratch pack.

Press START switch and
starts and heads load.

Press START switch and observe that heads unload and
pack stops rotating in approximately 30 seconds.

Set LOCAL/REMOTE swi tch
power is available).

Press START switch and
starts and heads load.

observe

Press START switch and observe that heads unload and
pack stops rotating in approximately 30 seconds.
Remove scratch pack.

Set MAIN AC circuit breaker to OFF.

observe

that

REMOTE

motor

(ensure sequence
that

4.23.5 Triac and Power Transistor Replacement
When rep:1 a c i ng t ria c s 0 r po we r t ran sis tor s ,
procedure should be performed:
1.

drive

the

motor

f 0 110 win 9

Remove power from drive as follows:
a.

Press START switch to
heads,

stop driv.e motor

and

unload

Set MAIN AC circuit breaker to OFF,

Disconnect power cable from site power receptacle.

Swing logic chassis open, slide power
remove power supply top cover.

Remove defective triac or power transistor.

Apply a coating of silicone grease to mating surfaces of
replacement triac or power transistor and power supply
(or heat sink 1n case of power transistor).

Install replacement triac or power transistor.

Replace cover on power supply and slide power supply into
normal :posi tion.

4-59

supply out,

and

Close logic chassis and cabinet rear door.

4.23.6 Power Supply Replacement (VDE)
The following procedure describes removal and replacement of the
entire power supply assembly used on VDE units.
1..

Remove power from drive as follows:
a.

Press START switch to
heads,

stop drive motor

and

unload

Set MAIN AC circuit breaker to OFF,

Disconnect power cable from site power receptacle.
NOTE
If drive is installed in-line with other
drives it will have to be pulled out of
line to remove side panels.

Remove cabinet side panels and open the rear door.

Remove the screw securing the power cord clamp to the top
of the power supply.

Disconnect the power cord from the power supply control
panel.

Disconnect plugs P3, P4, P6 on the side and P2, PS, P9 on
the rear of the power supply.

Disconnect the air hose at the rear of the power supply
by turning it counter clockwise.

Remove the hardware that secures the control panel end of
the power supply to the cabinet base.

Pull the power supply out the rear of the cabinet.
NOT!
The power supply may be reinstalled in
the cabinet and all cables are connected
to operate the drive with or without the
cover removed.
Ensure the blower hose
is connected.

To install the power supply, rest it on the cabinet base
and push it toward the front of the drive until the lip
at the rear of the power supply slips under the mounting
bracket.

1". chassis
Secure the control panel end of the power supply to the
with the hardware removed in step 9.
4-60

11.

Connect plugs P2, PS, P9 on the rear and P3, P4, P6 on
the side of the power-supply.
Attach the air hose by
turning it clockwise into the power supply.

12.

Connect the power cord to
supply control panel.

13.

Attach the power cord cord clamp to the top of the power
supply.

14.

Connect the power cord to the site power receptacle.

15.

Place the MAIN AC circuit breaker in the ON position.

16.

Perform DC voltage checks and +S V test and adjustment.

17.

Replace the cabinet panels and position the drive in line
with the other drives.

the receptacle on the power

4.23.7 -zeN (Power Amplifier) Card Replacement (VDE)
The following procedure details removal and replacement of the zeN
card used in VDE units (refer to Figure 4-20).
1.

Press the START switch to stop the drive motor and unload
the heads.

Remove the power supply
Replacement procedure.

Remove the power supply cover.

Note all lead connectiQns on the -ZCN
mounting brackets, and remove the card.

Position the replacement card on the mounting brackets
and secure it with the hardware removed in step 5.

Connect all leads to the -ZCN card.

Ir)stall the power supply top cover.

Install the power supply in the cabinet.

1" •

Per fo rm steps 1 and
checks proced ure.

using

the

manual

Power

Supply

card

controlled

servo

4.23.S -FNN (Relay) Card Replacement (VDE)
The following proced ure deta ils removal and replacement of
-FNN card used in VDE units (refer to Figure 4-20).
1.

the

Press the START switch to stop the drive motor and unload
the head s.

4-61

Remove the power supply
replacement procedure.

using

the

power

supply

. Remove the power supply cover.

Disconnect Pl at the -FNN card.

Remove the hardware that secures the card to the power
supply chassis and then remove the card.

Reverse steps 1-5 to install the replacement -FNN card.

4.23.9 -CPN (Control) Card Replacement (VDE)
The following procedure describes removal and replacement of the
-CFN card used in VDE units (refer to Figure 4-2").
1.

Press the START switch to stop the drive motor and unload
the heads.

Remove the power supply
replacement procedure.

Remove· the power supply cover.

Remove the -ZCN (Control) card.

01 sconnect connectors Pl,
card.

Remove the hardware that secures the CFN card to the rear
panel of the power supply. Remove the card.

Position the replacement -CFN card on the rear panel of
the power supply and secure it with the hardware removed
instep 6.

Reverse steps 1-5 to complete the installation.

P2,

using

P3,

the

and

power

P4 on

supply

the -CFN

4.23.10 -CBN (Rectifier/Pilter) Card Replacement (VDE)
The following procedure describes removal and replacement of the
-CBN card used in VDE units (refer to Figure 4-2").
1.

Press the START switch to stop the drive motor and unload
the heads.

2.
3.

Remove the power supply using
replacement procedure.
Remove the power supply cover.

4..

-ZCN (Power Amplifier) card.

Disconnect connectors Pl, P2, and P3 and the -CBN card.
4-62

the

power

supply

4.24

MOTOR RELAY BOX ASSEMBLY REPLACEMENT (VDE)

Turn off MAIN AC breaker located on the rear door.
Access the
motor relay box according to the procedure outlined in paragraph
3.8.3.
Refer to Figure 4-14.
Remove the two mounting screws
closest to the side panel.
Loosen the two mounting screws on the
motor side of the! relay box.
Carefully slide the relay box out
the right side.
Di sconnect P9 on the power supply.
Di sconnect
motor drive cable at P7. . Remove the three screws secur ing top
cover.
Circuit card may now be accessed.
Replace the relay box
assembly by reversing the above procedure.

4.25

READ/WRITE CHASSIS -XGN CARD REPLACEMENT

The -XGN card is located in read/write chassis location E05.
It
is mounted on the -XFN card in location E04 (the -XFN card is also
referred to as the Wmother W board).
Replacing the X-GN card
involves remov ing the read/wr i te chassis from the deck and then
removing the -XGN card from its position on the mother board
(refer to Fig ur e 4-21).
-XFN

-XGN
(E05)

PE2

Figure 4-21

PE3

Read/Write Chassis Card Replacement

4-63

9W56

Remove power from drive as follows:
to

and

stop drive motor

Press START swi tch
heads,

Set MAIN AC circuit breaker to OFF.

Remove disk pack.

Open cabinet top cover and remove deck cover.

Remove read/write chassis from deck as follows:

unload

Note connections and remove cable plugs PEl, PE2, PE3
and PES from read/write cards,

Remove cards
chassis,

E03

from

read)wr ite

Note connections and remove head
-XGN card starting with top plug,

cable

plugs

Remove fo ur sc r ews and washe r s sec ur 1ng r ead/wr i te
chassis to deck and remove chassis from deck.

E0l,

Remove -XGN card from
Figure 4-21:
l

E02

mot~r

and

board as follows.

from

Refer to

Remove four nuts and wa!:lhers secur Ing -XGN card to
mother board,
CAUTION
Use care not to damage pins.

b.
6.

Pry -XGN card from mother board.

Install replacement -XGN card to mother board as follows:
CAtrrION
Ensure that all pins go through the
proper holes and all pins are straight.
a.

Position -XGN card over pins on mother board, then
press cards together,

Secure -XGN card to
lockwashers and nuts.

4-64

mother

board

using

four

Install read/write chassis on deck as follows:
a.

Posi,tion read/write chassis on deck ensuring that
mother board engages the clip on actuatol housing,

Secure read/write chassis to deck using four screws
and wa she.r s ,
NOTE
Head cable connectors are keyed and plug
to mother board only one way.
Ensure
that cable between head-arm and plug is
not twisted or kinked.

Connect head cable plugs, starting with top plug (0),

Replace cards E0l, E02 and E03 in read/write chassis,

Connect cable plugs PEl, PE2, PE3 and PES.

Install deck cover and close cabinet top cover.

4.26 READ/WRITE CHASSIS -XFN (MOTHER BOARD) REPLACEMENT
The -XFN card is also referred to as theWmother" board. All the
other cards in the read/write chassis plug onto pins on the mother
board.
Replacing the mother board involves removing the read/
write chassis frcom the deck, disconnecting the other cards from
the mother board, then removing the mother -board from the
read/write chassis.
1.

Remove read/write chassis from deck and -XGN card from
mother board by performing steps 1 through 5 of
read/write chassis -XGN card replacement procedure
(paragraph 4.25).

Separate mother board from read/write chassis by removing
six screws and washers, and then set mother board aside.
Refer to Figure 4-21.

Position replacement mother board on read/write chassis
and secure with six screws and washers.

Replace -XGN card on replacement mother board as
instructed in step 6 of read/write chassis -XGN card
replacement procedure (paragraph 4.25). Al though step 6
refers to a replacement -XGN card, in this case the old
card is reinstalled.

Perform steps 7 and 8 of read/write chassis
replacement procedure (paragraph 4.25).

4-65

-XGN

card

4.27 SERVO PREAMP BOARD REPLACEMENT
This board is located in the servo preamp housing which is mounted
on the deck (refer to Figure 4-22). Replacing the board involves
removing the board from the preamp housing.

COVER

~,
~~

SERVO
/ PREAMP
BOARD

SERVO
HEAD
CABLE
HOUSING

9W57

Figure 4-22
1.

Servo Preamp Board Replacement

Remove power to drive as follows:
a.

Press START switch to stop drive motor
heads,

Set MAIN AC circuit breaker to OFF.

4-66

and

unload

Remove disk pack.

Open c,abinet top cover and remove deck cover.

Remove servo preamp board as follows:

4.28

Remove two hex head screws
cover and remove cover,

securing

servo

preamp

Disconnect servo head cable plug and output plug P8
frlom servo preamp board,

Remove two pan head screws inside preamp housing that
secure housing to deck,

Remove two hex head screws securing preamp circuit
board to housing and then remove circuit board and
set aside.

Install replacement servo preamp board as follows:
a.

Secure preamp circuit board to housing with two hex
head sc r ews,

Secure housing to deck with two pan head screws,

COI'lnect servo head cable plug and output plug P8 to
preamp circuit board,

Secure housing cover
screws.

to housing

using

two

hex

head

Install deck cover and close cabinet top cover.

SPEED SENSOR ASSEMBLY REPLACEMENT

The speed sensor assembly consists o,f the speed sensor and its
mounting bracket and is located on the pack sensor assembly.
The
following procedure (Figure 4-23) describes speed sensor assembly
replacement.
Speed sensor adj ustment is covered in the speed
sensor assembly adjustment procedure (paragraph 4.29).
1.

Remove power to the drive as follows:
a.

Press START switch
heads,

Set MAIN AC circuit breaker to OFF.

Remove disk pack.

Open cllbinet front door.

4-67

stop drive motor

and

unload

~ SPINOlE
SPEED
SENSOR

NOTES:

SHADED AREAS INDICATE SPEED SENSOR ASSEMBLY.
9WS8

Figure 4-23

Speed Sensor Assembly Replacement

Remove blower assembly.
Refer to blower motor
replacement procedure, paragraph 4.3, steps 3 and 4.

Remove speed sensor assembly as follows:

Disconnect speed sensor cable plug A3P3 and cut tie
wrap from speed sensor lead,

Remove locknut from speed sensor,

Remove speed sensor from switch base.

Replace speed sensor assembly as follows:
a.

Install new speed sensor in switch base,

Reinstall locknut on speed sensor, torque to 5 inch
pound maximum (15 inch pound maximum on the steel
sensors),

Connect speed sensor cable plug A3P3,

Secure speed sensor leadwlre to speed sensor swi tch
base with a tie wrap,
4-68

Perform speed

sen~or

adjustment.

4.29
SPEED SENSOR ASSEMBLY ADJUSTMENT
The speed sensor assembly must be adj usted whenever the spindle
assembly, pack sensor assembly or speed sensor assembly are
replaced.
The speed sensor assembly bas a lateral and a gap
adjustment.

The lateral adjustment is accomplished by moving the speed sensor
mounting bracket sideways until the sensor tip is in line with the
steel pin on the spindle pulley.
The gap adjustment is accomplished by turning the speed sensor to
achieve a specific distance between the sensor tip and the steel
pin in the spindle pulley (Figure 4-24).
BASE

47.5 1: 7.5 mm
(0.019 ± 0.003 INCHES)

SPINDLE PULLEY

,..-----1

SENSOR PICKUP

SPEED SENSOR POSITION CORREC~J
WHEN STEEL PIN AND SENSOR
PICKUP ARE CENTERED AS SHOWN

9\~59

Figure 4-24

Speed Sensor Assembly Adjustment

4-69

Stop spindle motor.

Remove disk

Set UNIT POWER circuit breaker to OFF.

Use feeler gauge to check that gap between sensor tip and
pin which is 0.019 (±0.003) inch (Figure 4-24).

p~ck.

CAUTION

Ensure that steel pln in pulley does not
contact speed sensor. Thls could happen
if speed sensor was significantly out of
adjustment as, for example, following
replacement.
5.

If requirement of step 4 is not met, adjust speed sensor
as follows:
a.

Loosen locknut on speed sensor assembly.

Adjust sensor assembly (clockwise rotation closes
gap and counterclockwise rotation widens gap) to meet
the requirements of step 3.
CAUTION
To avoid damage to the plastic threads,
do not over-tighten locknut in next
step.

Torque locknut to 5 (±l) inch-pounds.

Recheck dimension of gap.

Perform speed sensor output check (paragraph 3.21.2).

4.30
SPINDLB LOCKSHAFT RBPLACEMENT
The lockshaft is located within the spindle assembly.
Refer to
Figure 4-25.
However, the lockshaft is removed wi thout removing
the spindle.
There is no adjustment for the lockshaft replacement.
CAIlrION

When spindle assembly is removed from
drive or shipping container, do not
allow it to rest on pulley end of assembly. When it must be set down, lay it
on its side or on spindle faceplate.
Improper handling of spindle assembly
may cause damage to spindle bearings
which could result in premature failure
of spindle or even damage to disks and
heads.
4-78

LOCKSHAFT

~RETAINING

RING CLIPS HERE

PARKING BRAKE
MOUNTS HERE

3 EACH
_ _---- SCREW
9W60

Figure 4-25 Spindle and Lockshaft Replacement
1.

Remove

~~wer

from drive as follows:

Press START swi tch to
heads,

Set MAIN AC circuit breaker to OFF.

Open pat~ k access cover,
access cover open.

4-71

stop dr ive motor

remove disk

pac k ,

and

unload

leave

pac k

Open cabinet front door.

Remove blower assembly.
Refer to blower
replacement procedure, paragraph 4.3, step 4.

Refer to the following procedures for the removal of the
speed sens~r assembly.
Remove pack sensor assembly.
Refer
assembly replacement, paragraph 4.20.

pack

motor

sensor

NOTB

In the following step, do not remove
retaining ring securing springs in
spindle assembly.
This retaining ring
is located behind the flat waaher
removed in next step.
6.

Remove retaining ring and flat washer from lower end of
lockshaft. Refer to Figure 4-25.

Carefully raise lockshaft out of top of spindle assembly.

Lower replacement lockshaft until washer and retaining
ring can be snappe.d into place, thus securing lockshaft
in spindle assembly.
CAUTION

Push downward on lockshaft making certain that it is free to move downward
against internal spring force.
Lockshaft must be free and not binding.
9.

To reinstall pack sensor assembly, refer· to pack sensor
assembly replacement, paragraph 4.19.

19.

Per form pack-on swi tch adj ustment
4.19, steps 4 through 14.

11.

Reconnect leadwire to static groundspring.

12.

Perform static groundspring
paragraph 4.34, steps 4 and S.

13.

Reinstall blower assembly.
Refer to blower
replacement procedure, paragraph 4.3, step 15.

14.

Close cabinet front door.

4-72

proced ure,

adjustment

paragraph

procedure,
motor

CAUTION
When spindle assembly is removed from
dr ive or shipping container, do not
allow it to rest on pulley end of
assembly. When it aust be set down, lay
it on its side or on spindle faceplate.
Improper .handling of spindle assembly
may cause damage to spindle bearings
whie'h could result in prellature failure
of spindle or even damage to disks and
heads.
4.31
SPINDLE ASSEMBLY REPLACEMENT
The spindle assembly (refer to Figure 4-25) includes the spindle
and lockshaft.
It is removed from the top of the deck wi th the
pack sensor assembly still attached. The pack sensor assembly is
then transferred to the replacement spindle and they are both
replaced in the dr ive.
The spindle must be real igned to the
carriage following a spindle replacement and this is covered 1n
the spindle to carriage alignment procedure, paragraph 4.32.
1.

Remove power from drive as follows:
a e 'Press, START swi tch
heads,
bo

stop' dr ive . mo tor

and

unload

Set MAIN AC circuit breaker to OFF.

Remove disk pack.

Open dr ive cabinet front door.

Remove blower assembly (refer to blower motor replacement
procedure, paragraph 4.3, step 4).

Identify leadwires to pack-on switch
groundspring and then disconnect leadwires.

Disconnect speed sensor plug A3P3.

Open cabinet rear door.

Remove drive belt as follows (refer to Figure 4-4):

and

static

Remove idler springs,

Move motor mounting plate towards spindle to rel ieve
tension from drive belt off pulleys and set aside.

Remove p,arking brake assembly as follows (refer to Figure
4-18) :
a.

Open pack access cover,
4-73

10.

Remove six screws and washers securing brake cover to
shroud and then remove cover and set aside,

Remove two screws securing parking brake assembly to
deck casting and then remove and set assembly aside.

Remove
4-25):
a.

spindle

assembly

follows

(re~er

Figure

Remove three screws and washers (located under deck)
securing spindle assembly to deck.
CAlr1'ION
When removing spindle, use care not to
damage pack sensor assembly.

Lift spindle assembly straight up and off from dowel
pins and remove from drive.
NOTE
In step c, position pack sensor assembly
so pack-on switch is as close as
possible to dimensions shown in Figure
4-16.
Thi~ minimizes final adjustment
when spindle is replaced in drive.

Remove pack sensor assembly from old spindle assembly
and install on replacement spindle assembly.
NOTE
Ensure mating sur faces of spindle and
deck are clean.

11.

Lower replacement spindle into posl t ion on deck 0 r ien t i ng
pack se.nsor assembly toward dr ive mo tor and fit spi ndl e
over pins in deck. Refer to Figure 4-25.
NOTE
Tighten spindle down evenly, keeping its
bottom surface parallel to deck surface.

12.

Secure spindle assembly to deck using three screws and
washers.
Leave screws loose enough to allow lateral
movement of spindle to carriage alignment.

13.

Perform spindle to carriage alignment
(paragraph 4.32, steps 4 through 22).
NOTE
Apply Loctite pri •• r, grade N, and Loctite grade C to screws used in step 14.

4-74

procedure

14.

Secure parking brake to deck using two screws (paragraph
4.22).

15.

Perform parking brake adjustment procedure, steps
through 14.

16.

Replace drive belt as follows:

Position drive belt on drive motor pulley and then
move drive motor mounting plate towards spindle and
slip drive belt around spindle pulley,

Install idler springs,

Manually rotate spindle to seat drive belt,

Close rear door.

17.

Perform pack-on switch adjustment
4.19, steps 4 through 11).

procedure

(paragraph

18.

Replace ground lead on static groundspring and perform
static groundspring adjustment procedure (paragraph 4.34,
steps 4 and 5).

19.

Reconnect speed sensor cable plug P3.

20.

Perform speed sensor adjustment procedure (paragraph
4.29, steps 4 through 7).

21.

Reinstall blower assembly.
Refer to blower
replacement procedure, paragraph 4.3, step 15.

22.

Close cabinet front door.

23.

Perform speed sensor output check procedure
3.21.2) •

motor

(paragraph

4.32
SPINDLE TO CARRIAGE ALIGNMENT
This adjustment is required whenever the spindle is loosened from
the deck casting.
A similar adjustment must be made when the
actuator is loosened from the deck. However, this is described in
the actuator assembly replacement procedure (paragraph 4.2).
The spindle and carriage are properly aligned when carriage motion
is along a radial line from the axis of rotation of the spindle
assembly. The following describes spindle to carriage alignment.
1.

Remove power from drive as follows:
a.

Press START switch to stop drive motor
heads,

4-75

and

unload

b •. Set MAIN AC circuit breaker to OFF.
2.

Remove disk pack.

Raise top cover, then open pack access cover
possible. Refer to Figure 4-26.

as far

WITH BOTH COVERS OPEN AND"

~IN THIS POSITION IT IS
~ POSSIBLE TO ACCESS DECK

AND SHROUD AREA FOR
MAINTENANCE

9W61
i

Figure 4-26

Cabinet with Pack Access and Top Covers Open

4•

Re m0 v e he ads fro m sur fa c e po sit ion s 1 7 and 1 8 a s
instructed in head-arm assembly replacement procedure
(paragraph 4.8, steps 5, 6 and 7).

Install and posi t ion carr iage al ignment
(refer to Figure 4-27):

arm as

follows

Install carriage alignment arm in surface position 18
and parallel to the deck. Torque clamp screw to 4 (~
1/2) inch-po unds,

Slowly extend carriage until heads load, then forward
until carriage alignment arm clears edge of spindle
and is positioned approximately over spindle hub,

c•

Lo 0 sen he a d - arm c lam p s c r e w , and til t car ria 9 e
alignment arm downward until it aligns with spindle
hub as shown in Figure 4-27, then torque clamp screw
to 4 (± 1/2) inch-pounds,

Close top cover, thus allowing pack access cover to
open fully.

4-76

CARRIAGE

ARM MUST BE INITIALLY SET PARALLEL
OR IT CANNOT BE POSITIONED OVER HUB

HUB

ARM

~ CARRIAGE
WHEN POSITIONED OVER SPINDLE
HUB, ARM MUST BE TILTED TO
ALIGN IT PROPERLY WITH HUB
(SEE INSERT BELOW)

HEAD
SURFACE
POSITION
CARRIAGE 18
ALIGNMENT
ARM

~~r
pc~

-----~

SPINDLE

HU~

-\ \

A~~)~~t;OWEl
NOTES:

CARRIAGE

'>-

~~rb\\ L-

MILLIMETERSj~

0.0001-0.0002
(0.002-0.004 INCHES)

HEADS 17 AND 18
ARE REMOVED, ALL OTHER HEADS
WILL REMAIN IN POSITION ALTHOUGH
NOT SHOWN IN THIS ILLUSTRATION
Figure.4-27

AL1~~MENT

9W62

Spindle to Carriage Alignment

Check to see if clearance between carr iege a1 ignment arm
and spindle post is as specified in Figure 4-27.
If
clearan(!e is not as specified, proceed to step 7.
If
clearance is as specified, proceed to step 20.

Raise
4-26.

Unload heads and remove car r iage al ignment arm.

top cover

that

covers are

4-77

shown

Figure

Close top cover allowing pack access cover to fully open.

10.

Remove six screws and washers securing
cover to shroud and remove cover.

11.

Raise top cover so
4-26.

12.

Install and position carriage alignment arm as instructed
in step S.

13.

Close top cover allowing pack access cover to fully open.

14.

Loosen three screws securing spindle to deck,
allowing lateral movement of spindle assembly.

parking

brake

that covers are as shown in Figure

thus

NOTE
If specified clearance is obtained in
step 15, proceed to step 17.
If it is
too far out of alignment to be adjusted
in this manner, it will be necessary to
move the actuator housing to obtain the
proper clearance.
In this case proceed
to step 16.
15.

Using spindle adjustment tool, move spindle
clearance specified in Figure 4-27.

obtain

16.

Align spindle to carriage by moving actuator housing as
follows:
a.

Move spindle until dowel pins are centered in spindle
slots (refer to Figure 4-27), and then tighten three
screws securing spindle to deck,

Raise tnp cover so that covers are as shown in Figure
4-26,

Unload heads and remove carriage alignment arm,

Close pack access and top covers,
NOTE
Upon coapletion of step ., spindle to
carriage alignment will have been
performed.
Therefore, do not complete
steps 17 through 24 of this procedure.

Perform actuator assembly replacement procedure
(paragraph 4.2).
However, instead of replacing the
actuator housing in steps 17, 18 and 19, only loosen
the screws securing it to the deck.

4-78

17.

Secure spindle by tightening three spindle screws.

18.

Recheck clearance and if it is incorrect, repeat steps 14
and 15 until proper clearance is obtained.

19.
20.

Raise top cover as shown in Figure 4-26.
Unload heads-and remove carriage alignment arm.

21.

Replace heads (removed in step 4) as instructed in
head-arm assembly replacement procedure ( pa rag r a ph 4 • 8 ,
step 9).

22.

Close top cover allowing pack access cover to fully open.

23.

Replace parking brake cover using six screws and washers.

24.

Perform head alignment procedure (paragraph 3.17.2)
heads in surface positions 17 and 18.

for

4.33
STATIC GROUNDSPRING REPLACEMENT
The static groUlndspring is mounted on the static groundspring
mounting bracket which, in turn, is mounted on the pack sensor
assembly.
This procedure describes removal and replacement of the
groundspring from its mounting bracket.
Adjustment is required
following replclcement and this is described in the static
gioundspring adjustment procedure (paragraph 4.34).
1.

Stop spindle motor.

Remove disk pack.

Set UNIT POWER circuit breaker to OFF.

Remove left side panel (as viewed from front).

5•

Re fer to
leadwire.

Remove self-threaded screw, lockwasher, terminal lug, and
groundspring from switch base bracket.

Install replacement groundspr ing on swi tch base bracket
using screw, lockwasher, and terminal lug.

Perform static
(paragraph 4.34).

Connect groundspring 1eadwire.

10.

Replace side panel.

Fig ur e

4 - 28

and

rem 0 v e s t a tic

groundspring

4-79

adjustment

9 r 0 un d s p r i n9

procedure

LEAD WIRE
TERMINAL
STATIC
GROUND
SPRING

~PACK SENSOR
ASSEMBLY

9W63

Figure 4-28

Static Groundspring Adjustment

4.34
STATIC GROUNDSPRING ADJUSTMENT
This adjustment properly positions the static groundspring in
relation to the lockshaft.
A check is also made to ensure the
groundspring has the correct tension.
1.
2.

Stop spindle motor.
Remove disk pack.

Set UNIT POWER circuit breaker to OFF.

Remove left side panel (as viewed from front).

4-8"

Refer to Figure 4-28 and visually check that groundspring
is approximately centered on lockshaft.

If required, loosen screw secur ing groundspr ing to
mounting bracket and center spring as required. Tighten
screw.

Place an 0.019 (+ 0.003) inch non-metallic feeler gauge
between groundsprlng and lockshaft.

Hook a push-pull gauge to outer end of gro undspr ing.

The for(~e required to allow feeler gauge to fall free
should be 125 (+ 25) grams.
It should be applied
perpendicular to the spring.

l~.

If required, adjust set screw in switch base bracket for
proper spring tension.

11.

Replace side panel.

4.35
VELOCITY 'TRANSDUCER ASSEMBLY REPLACEMENT
The velocity transducer assembly consists of the coil housing,
transducer core and the extension rod. Refer to Figure 4-28.

The coil housing is secured to the magnet assembly while· the
transducer core (located inside the coil housing) is connected to
the carriage by the extension rod.
As the carriage is moved to
position the heael-arm assemblies, the transducer core and extension rod move with it. The following describes replacement of the
transducer coil housing and core.
1.

Remove p<)wer from dr ive as follows:
a.

Press START switch
heads,

stop drive motor

Set MAIN AC circuit breaker. to OFF.

and

unload

Remove disk pack.

open cabinet top door and remove deck cover.

Disconnect yellow voice coil leadwire.

Remove transducer coil and core assembly as follows:
a.

Manually move carriage forward until end of extension
rod can be unthreaded from carriage. Refer to Figure
4-29. However, do not remove transducer core and rod
un til ins true ted to do so,

4-81

CORE
COIL HOUSING

SPRING

"\\ \~~.~/~
\
~

END CAP

EXTENSION ROD
9W65

Figure 4-29

Velocity Transducer Replacement

Remove velocity transducer cable plug P4,

c•

Rem 0 vet wo s c r e wsan d was her sse cur i n9 vel 0 cit y
transducer end cap to magnet and remove end cap,

Carefully remove coil housing and
(connected to extension rod) from
aside.

transducer core
magnet and set

CAUTION

Transducer core can be ruined if it
comes in contact wi th a ferromagnetic
object.
6.

Carefully remove replacement coil and core from shipping
container and set on a non-ferrous surface.

Determine which end of replacement transducer core is to
be connected to extension rod as follows.

4-82

NOTE
Replacement transducer core should have
a
red dot or stripe at one end
indicating that end is the north pole of
the leore. Therefore, the
unmarked end
is the core' s south pole. The unmarked
end (south pole) always connects to the
extension Tod.
Whether or not core has
a marked end, always check replacement
core to determine polarity.
a.

Identify end of defective transducer core that
connects to extension rod.
Place unmar ked end (no
red mark) next to extension rod end of defective
transducer.
If cores repel each other then you have
identified the extension rod end.
If cores' attract
each other, opposite end connects to extension rod.

After determining which end of replacement transducer
core to connect to ,extension rod, place replacement
transducer core on a non-ferrous surface.
CAUTION
Extension' rod must be grasped at end
nearest transducer core when separating
or connecting the two.

Carefully unthread
extension . rod
from
t r ansd uc'er core assembly and set defective
core aside.

Thread extension rod into end of transducer core
observing that polarity of replacement core is same as
old transducer core. Wipe off excess Loctite.

10.

Insert replacement transducer core and extension rod into
replacement coil housing until core is' completely
contained in housing.

11.

Install replacement transducer core and coil
magnet as follows:

defective
tr ansd ucer

housing

'Insert
replacement
coil
housing,
containing
transducer core and extension rod, into magnet,

Position velocity transducer end cap and spring on
magnet and then secure end cap to magnet with two
screws and washers,

Apply one drop of Loctite, Grade C, to extension rod
threads and then thread extension rod into carriage,

Connect velocity transducer cable plug P4.
4-83

12.

Manually move carriage back to retracted stop.

13.

Install scratch disk pack.

14.

Set MAIN AC circuit breaker to ON.

15.

Ensure velocity transducer output has proper polarity by
performing following check:
a.

Open cabinet rear door,

Open logic chassis and remove card cover,

Connect oscilloscope channell
TPE,

(using 10X probe)

A20 -

Trigger oscilloscope positive internal,

Press· START switch to start drive motor,
CAUl'ION
Refer to paragraph 3.15 (steps 4 and 5)
when performing steps f and 9.
~eads,

Manually load

Manually move carriage in a forward direction and
observe that oscilloscope waveform goes in a negative
direction.
If signal goes positive, transducer core
is in backwards.
In this case, remove core, turn it
end for end and repeat this check,

Manually retract heads as instructed in
manually positioning carriage procedure
3.15),

step 7 of
(paragraph

Press START swi tch
heads.

and

stop dr ive motor

16.

Set MAIN AC circuit breaker to OFF.

17.

Reconnect yellow leadwire to voice coil.

18.

Replace deck cover and close top cover.

19.

Perform procedures listed below.
test

Servo
system
3.17.2.7).

Velocity transducer gain uniformity check (paragraph
3.18.2.15) •

4-84

and

adj ustment

unload

(paragraph

4.36
VOICE COIL FLEX LEAD REPLACEMENT
The voice coil flex leads are attached between the carriage and
actuator housing.
They consist of flexible copper strips
separated by flexible insulators.
The following descr ibes
replacement and adjustment of the flex leads.
Adjustment is
required so they do not bind, kink, or restrict carriage travel.
1.

Remove power from drive as follows:
a.

Press START switch
heads,

stop drive

Set MAIN AC circuit breaker to OFF.

motor

and

unload

Remove disk pack.

Open drive top cover and remove deck cover.

Remove connectors from cards E01, E02, and E03 in read/
write chassis, then remove these cards and set them
as ide.

Disconnect voice coil leadwire
con n e c to r ( ref e r to Fig u r e 4 - 3") •

Remove v,oice coil flex lead as follows:

plug

from

voice

coil

Remove nut, insulated screws and washers securing
voice coil leads and flex lead mounting bracket to
actuator housing,

Separate flex leads from mounting bracket and
attaching hardware, then set bracket and attaching
hardware aside,

Po si. t ion
housing,

Manually extend carriage until end of
attached to carriage is easily accessed,

Disconnect number one leadwire by removing screw nut
and washer securing it to flex lead,

Remove insulated screw and nylon washer securing
number two leadwire, flex leads and backing plate to
carriage,

RemClve voice coil flex heads and backing plate from
actuator housing and set aside.

free

end

4-85

flex

leads

out

actua to r

flex

leads

LEADWIRE

FLEX LEAD
MOUNTING
BRACKET

NYLON WASHER
INSULATED SCREW

9W66

Figure 4-30

Voice Coil Flex Lead Replacement
CAUTION

Handle replaeement flex leads carefully.
Do not bend or twist them.
Also ensure
that flex lead copper strips are
parallel when installation is complete.

4-86

Install replacement voice coil flex leads as follows:
a.

Position flex leads inside actuator housing as shown
in Figure 4-30.
Note, however, that the mounting
bracket is not in place,
NOTE
Apply one drop of {Locti te, grade C, to
screws used in steps b, c and d.

Secure number two
to carr'iage
washer,

Secure number two leadwire to
screw, nut and lockwasher,

platE~

Ieadwire, flex lead and backing
using insula ted screw and nylon
flex

conductor

using

d.
8.

Secure flex lead mounting bracket and flex leads to
actuator housing as shown In Figure 4-30.
Inspect and adjust voice coil flex leads as follows:

Ensure that number one flex lead does not touch
carriage casting.
If necessary, carefully bend lead
until this requirement Is met,

Ensure that copper strips are parallel.
If
necessary, loosen all screws and adjust copper strips
until they are parallel,

Check that flex leads travel freely through the
entire range of travel without linking or interfering
with carriage movement.

Grasp coil through open.!ng in top of magnet assembly.
Carefully and slowly push coil forward to extend heads.

10.

Once head arms have cleared the cams, gently slide
carriage and co.!l assembly back and forth along the full
length of rails.
While moving coil, be aware of any
possible irregular i ty (bumps or jer ks) in movement.
A
sudden irregularity indicates dirt on the rails and
bearings.
Do not confuse pressure of flex leads with a
sudden ir'regularity in motion. Pressure from leads is a
smooth change.

11.

Reconnect voice coil leadwires.

12.

Replace voice coil leadwires.

13.

Manually move heads back to fully retracted position.

14.

Replace plastic magnet shield on magnet.

15.

Replace deck cover and close top cover.
4-87

APPENDIX A
TB3A2 PIELD TEST UNIT

A.I
INTRODUCTION
The TB3A2 Field Test Unit (FTU) is a portable, self-contained tester for exercising and simulating on-line operations in the RM05
Disk Subsystem.
The FTU is housed in a suitcase-type carrying case that provides a
control panel, a logic board, and an integral power supply.
The
ease conta ins space for stor ing the power cable, all necessary I/O
cables, and a head alignment card. The head alignment card plugs
into the logic chassis of the drive and permits individual head
alignment, using a null meter mounted in the FTU control panel.
A.l.1
Operating Voltage
The FTU normally uses a 120 Vac, 50 or 60 Hz power source.
configure the FTU for 240 Vac operation, proceed as follows:
1.

Open

Raise the control panel,

Remove the head alignment card from -its compartment on
top of the power suppl y box,

Remove the four screws securing the cover plate of the
power supply. Remove the cover plate,

thE~

FTU cover.

Unhinge the cover and set it aside,

Remove the jumper straps connecting terminals land 2,
terminals 3 and 4 of AlTBI (Figures A-I and A-2),

t~en

Install both jumpers to connect terminals 2 and 3,

Replace and secure the power supply cover plate,

Replace the head alignment card in its compartment,

Attach a 120 to 240 Vae conversion plug to the FTU power
cord.

The FTU is now ready for 240 Vae operation.

A-l

POWER SUPPLY BASIC COMPONENT LAYOUT
-I

RFI

AISI

a
.U

AITBI

& &

-5V
SUPPLY
AITI

AICBI

+5V
SUPPLY
AIT2

NOTES:

VOLTAGE POT (SCREWDRIVER ADJ)

&OVERVOLTAGE POT (SCREWDRIVER ADJ)

Figure A-l

FTU Power Supply Layout

A.l.2
I/O Cables
The FTU comes equi pped wi th two I/O cables.
The A cable has a
7S-pin block-type connector on one end and a 60-pin fla t-cable
connector on the other end for connection to the drive.
The B
cable has a 34-pin block-type connector on the tester end and a
26-pin flat-cable connector on the drive end (Figure A-3).
A.l.3
Head Alignment Cable
.
In addition to the head alignment card described earlier, the FTU
comes equi pped wi th a 4-wire head al ignment cable.
This cable
connects between the logic chassis of the drive and the
appropr iate jack in the dr ive' s read/wr i te assembl y (see Fig ure
A-4). A pair of test leads, which also comes with the FTU, then
connects between the banana jacks on the head al ignment card and
the null meter on the FTU control panel.
A.2
MODES or OPERATION
The TB 3A2 FTU prov ides five access (seek)
modes, and two modes for selecting heads.

modes,

four

read/wr i te

NOTE
Perfor.ing any write operations will destroy formatting on the pack.
A.2.1
Direct Seek
The drive under test will perform a single seek to the track number set in the CYLINDER ADDRESS switches on the FTU control panel.
A-2

-5VDCSUPPLY

OUTPUT

SENSE

OUTPUT

SENSE

+5 V DC SUPPLY

-vec

OUTPUT

SENSE

vee

SENSE -

OUTPUT
FAN
MI

tiv
A

~-5V

NOTES:

6WIRING SHOWN FOR 110V OPERATION

CASE

LOGIC BOARD +5 V BUS
CONTROL PANEL BOARD
+5V BUS
~ONTROLPANELBOARD

-5VBUS
......
Lll_·_G_N_D---.ro- LOG I C BOA R D G NO BUS

FOR 220V OPERATION, JUMPER '·2 AND 3·4 ARE
REMOVED AND JUMPER 2·3 IS ADDED. THE
RESULTANT IS SHOWN BELOW

CONTROL PANEL BOARD
GND BUS

AI~
A

THESE ARE REPLACED AS A UNIT AND THEREFORE

~INDIVfOUAL COMPONENTS (OTHER THAN TRANSFORMERS) ARE NOT SHOWN
6REFER TO KEY TO LIDGIC FOR +5 V, -5 V AND GND BUS CONNECTIONS

Figure A-2

FTU Power Supply Wiring Diagram

A-3

P3B
SD-PIN FLAT
CONNECTOR

P2B
26·PIN FLAT

CON~

MA-OI'

Figure A-3

Tester I/O Cables

A-4

HFSV HEAD ALIGNMENT
CARD PLUGS INTO CARD SLOT
IN DRIVE LOGIC CHASSIS
(SEE NOTE)
TOJ CKS ON
. HEAD ALIGNMENT CARD

FITS OVER WIW PINS FOR
HEAD ALIGNMENT CARD SLOT
IN DRIVE LOGIC CHASSIS
MA..ou2

Figure A-4

Head Alignment Connections

A-S

A.2.2
Continuous ,Seek
The drlve under test will perform repetitive seeks between any two
Operation will continue until
tracks selected by the operator.
the START/STOP swi tch on the FTU control panel is moved to STOP
(STOP switch actuated).
A.2.l
Sequential Porward Seek
The drive under test will perform single-track incremental seeks
un til the las t t r ac k is rea c h ed , then seek to track 000, and
continue incremental seeks in the same manner until the STOP
switch is actuated.
A.2.4
Sequential Reverse Seek
The drive under test will perform single-track decremental seeks,
starting with the track set in the CYLINDER ADDRESS switches,
until track 000 Is reached. The drive will then return to the set
track and repeat the operation until the STOP switch is actuated.
A.2.S
Random Seek
The drive under test will perform seeks to random tracks as selected by a free-running counter within the FTU.
Operation will
continue until the STOP switch is actuated.
A.l
READ/WRITB MODES
The TB3A2 FTU generates serial NRZ write data at a rate determined
by the servo clock signals transmitted from the unit under test.
When a repeatable access mode is selected, that is, any mode except direct mode, a read/write operation will be completed at the
selected cylinder. Then the FTU will initiate a seek to the next
cylinder address determined by the access mode and the read/write
operation will be repeated. This seek-read/write sequencing will
continue until the STOP switch is actuated or an error occurs.
For direct seeks, the read/write operation will continue at the
selected track or cylinder until the STOP swi tch is actuated,
depending on the head-select mode.
The number of tracks read or written during each read/write operation is controlled by the mode of head selection chosen. For manual head selection, only the track under the head selected by the
HEAD ADDRESS switches will be read or written.
For sequential
head selection, the heads will be sequenced so as to read or write
each track in the cyl inder.
When the highest numbered head or
cylinder track has been exercised, the drive will seek to another
cylinder (except in direct seek) and the read/write operation will
be repeated at that new cylinder, starting with head 0S.
A.l.l
Write Por.at
With the FTU WRT-RD SELECT switch set to WRT FORMAT, the FTU will
write each selected track with the appropriate track address and a
repetitive a-bit data pattern that has been set in the DATA
PATTERN switches on the FTU control panel. The FTU also provides
a means for indicating a defective track when using, the write
format mode,.

A-6

A.3.2
Write
Wi th the FTU WRT-RD SELECT swi tch set to WRT, the FTU wi 11 wr i te
the repetitive 8-bit data pattern on the selected track.
The FTU
will, however, first read and verify the track address.
A.3.3
Read
Wi th the FTU WRT-RO SELECT swi tch set to RO, the FTU wi 11 read the
data from the selected' track.
It will first read and ver ify the
track address.
A.3.4
Write Then Read
Wi th the FTU WRT-RO SELECT swi tch set to WRT-RD, the FTU wi 11
verify the track address and write the 8-bit data pattern on the
selected track during one revolution of the drive.
It will then
again verify the track address and read back the data during the
second revolution.
A.3.5
Off
The OFF posi tion of the WRT-RD SELECT swi tch is
operations and head alignment procedures.

used

for

access

A.4
CONTROLS AND INDICATORS
Except for the power swi tch and circui t breaker moun ted on the
power supply box, all controls and indicators for operation of the
TB3A2 FTU are on the control panel (Figure A-S). The controls and
indicators are described below, moving from top left to bottom
right across the panel.

A-7

DAT...
STR08E
SERVO
WRT
OffSET
+SV -SV + EARLY fLAG

~t ~I

0 0

~CYUND'.
r - HO+ EAR CNT
CH...R CHT
AEAD D...T...
UNIT NO

SEa WAT
PWR INHIBIT

cj\ @

SERVO HAM

DISPLAY SELECT

LATE

XTAL MAIHT

UNIT
f ...ULT RE...DY

OFF

NAM

INITIALIZE

TPI
LO

ACCESS MODE

MMO

@
SMD
PLUG
V... L1D

•
r

NIT

~W.T~T
WRT

@@ @@ @SEC
32

S-C S-M WAT
EAA EAA PAOT

SEC SEEK
30 32 EAR

0 0

0 0 0

000

EAA BYP"'SS
ADOR O...TA

0 0
10

:T'AE...O
Off

0 00

•

\il' (3)

7 6

AUN

0
0

srART

RESET STOP

000
0
2

'ij) cij\ @
5

@c8@1
2

~: @

«l; 'w '6' ;;a. \3' -W ·tv'tV,tV1

2Sti 12.

FIXED

SEa

BOTH ~)
MOV.... LE

'tV

M ...N

•

@SECTOR
M ...RK

@INOEX
MARK

@~L

@REAO
DATA
,@IITS-,

@WAITE
D... TA

o •

@WRITE
, CLK

@4@

@READ
CLK

@t
@3

r=-- ~A_O ADDRESS --:-1
c~ <,4> <tV
32 'I

@o... r ...
ERR

CYLINDER ...OORESS

1024 512

Rll

000
3

...ODR
ERR

o ... rA P... TTERN

I r-.

WRT READ

I ~L I

000

DISPLAY

SEa fWD
DIRECT
CONT
RAND

WAr -AD SELECT

11 CHII

UNIT CLK
SEL EAA

ctl~Q·'·

HI
HEADS
SILOt

... OOA O...T...
EAA
EAA

cj\ 'it @
4

@.
@7
@.

@WRITE

GATE
@AEAD

GAlE
@CYL
SElECT

@HEAD
0 SElECT
GND
CONTROL
SElECT

....
Fig ure A-S

TB3A2 Control Panel

+5 V,

-s V
indicators.

Indicate that the respective
voltages are present.

SERVO OFFSET
switch

A 3-position switch with center ·off.·

power

supply

Commands the drive to offset
the carriage in the positive
direction (toward the spindle).

Center

Nominal positioning
set) •

(no off-

Commands the drive -to offset
the carriage in the negative
direction
(away
from
the
spindle) •
NOTE
The START/STOP swi tch must be
actuated to effect any change
in offset by the drive when in
direct mode.
DATA STROBE
switch

WRT FLAG

A 3-position switch with center "off."
EARLY

Moves the drive's read strobes
from nominal to an earlier time
with respect to data.

, Center

Dr ive
strobes
timing.

LATE

Moves the drive's read strobes
'from nominal to a later time
with respect to data.

nominal

When moved up, this switch causes a defective
track flag bit to be inserted in bit 6 of
address word 1, provided that:
o

WRT-RD SELECT switch is set to WRT FORMAT.

ACCESS MODE switch is set to DIRECT.

Head-select

swi tch

(SEQ-MAN)

set

MAN.

XTAL/SERVO
swi tch

A crystal oscillator within the
FTU provides a nominal 9.667
MHz clock signal.
Used for
tester maintenance.

XTAL

A-9

MAINT/NRM
switch

SEQ PWR/OFF
switch

WRT INHIBIT/NRM
switch

MAINT

Used to perform maintenance on
the FTU wi thout a dr ive connected.
Provides pseudo ready
and on cylinder signals to simulate a dr ive response.
It is
al so used d ur ing head al ig nments.

NRM

Normal testing of a drive
done in this position.

SEQ PWR

In this posi tion, the FTU commands the drive to power-up,
prov ided tha t

The dr ive is in the remote
mode.

Pr imary power is available
at the drive.

The drive's START switch is
ON (indicator lit).

OFP

In this position, the FTU cannot power-up the drive.

WRT INHIBIT

Prevents writing by the drive
even though all other FTU
swi tches are set to per form a
write operation.

NRM

Allows a normal write operation
in the drive# provided all
other FTUswitches are set to
perform a write operation.

INITIALIZE

When moved to the up position, this momentary contact switch provides an In it ial i ze
signal to the drive.

TPI swi tch

Not used.

MMD/SMD switch

Not used.

HEADS swi tc h

Place in the down posi tion to select a drive
which has 19 disk surfaces.

PLUG VALID
swi tch

With PTU's DISPLAY SELECT switch set to UNIT
NO. so as to display the PLUG VALID indication, proceed as in Table A-l.

A-1S

Table A-l
-.- Display Light
(Plug Valid Indicator)
ON

Plug Valid Indication

Meaning

To Select Drive

Logical address
plug is installed
in drive.

1. Set
up.

PLUG

VALID switch

the
switches

thr ee
UNIT
to desired

2. Se t

d r i v e n urn be r

OFF

Logical address
plug is not installed in drive.

1. Set PLUG
down.

( 0 -7 ) •

VALID switch

2. Set

all
t hr e e
UN I T
swi tche s
down
to
pseudo-select unit 0.

UNIT switches

Used
to
ind icate
the
binary val ue of the thr ee
select address lines to
the drive. This code must
match that of the log ical
address plug in the drive
under test.

421

Selects the dr ive under
test for either 30- or
32-sector operation.

SEC 30/32 switch

A-II

ACC ESS MODE .
switch

DISPI.AY SELECT

A five-position rotary switch that controls
the seek (access) mode of the drive under
test.
SEQ REV

Sequential Reverse - The dr ive
seeks to the address in the FTU
CYLINDER ADDRESS swi tches, sequences down to 0 and then repeats.

SEQ FWD

Sequential Porward - The dr ive
per forms a ser les of incremental seeks, starting with the
address that is in the cylinder
address reg ister (CAR) at the
start of the operation.
When
the
maximum
cylindei
is
reached, the cycle begins again
at address 0.

DIRECT

Direct - The drive seeks to the
address in the CYLINDER ADDRESS
switches.
Seeking to another
address requires changing the
add ress in the swi tche sand
manually initiating another
seek operation by actuating the
START switch.

CONT

Continuous - The drive seeks
alternately between the address
in
the
CYLINDER
ADDRESS
swi tches and tha t in the CAR.
The contents of the CAR do not
change during this operation.

RAND

Random - The drive seeks to
random addresses generated by
increasing the count in the CAR
during the time that the drive
is not "on cylinder".

A five-position rotary switch that controls
the eleven DISPLAY lamps on the FTU control
panel.
The interpretation of the display is
shown in Pigure A-6.
When the swi tch is set
on READ DATA, the cyl inder address will be
displayed as long as the FTU is running. The
data pattern read will be displayed if the FTU
has stopped because of a data error;
otherwise, the display will be 0s.

A-12

OISPLAY SELECT SWITC ...
POSITION
CYLINDER

HD + ERR CNT

-CHAR CNIT

. tr-------OISPLAY-BIT L E D ' . - - - - - - - .

000

612

256 128 84

000

8
7 8
4
8
1
2
LERROR COUNT..J

0
2

000

1
3
4
2
0
16 8
2
4
1
LHEAD REGlSTER-l

000

0
16

- 8192

4096 2048 1024

512 256 128

84 ·32

000

7
7
I

6
8

000

4
4

3
3

2
2

READ BITS

00
9

000
6

4
4

0
0
I

000

1 PLUG
VALID
MA.-0639

Figure A-6

Display Select Switch

A-13

A five-position rotary switch that determines
the manner in which data will be exchanged between the FTU and the drive under test.

WRT-RD SELECT
switch

WRT FORMAT

Write Format
Writes the
correct track address and a
prescribed a-bit data pattern
field on each selected track.
The format is as shown in
Figure A-7.

ADDRESS
FIELD

DATA~A~~EL_D

ZEROS

________

HOME ADDRESS
' GAP . ,
PROTECT

~~
I

INDEX
GAP

I DATA WORD 2 I
A

....
HEAD
ADDRESS

8·81T DATA PAmRH
IS REPEATED FOR THE
ENTIRE DATA FIELD.
EXCEPT THAT 81T 7 OF
WORD 1 IS A SYNC 81T

"0" IN DICATES
UNUSED BIT

CYLINDER
ADDRESS

WRITE FLAG BIT
ADDRESS SYNC 81T

DATA SYNC BIT

NOTI
Is not the

This for.at
standard DIGITAL for.at.
Pigure A-7

sa..

......,

the

Track Format

WRT

Write - Writes a preselected
pattern in the data field of
each selected track, after
fi rst ver i fying the track address.

Read
Verifies the track
address,
then
reads
the
selected pattern.

WRT.READ

Write Then Read - Verifies the
track address, writes the data
field on the selected track,
then reads the track.
(Operation requires two revolutions.)
A-14

OFF

Off - Disables all read/write
functions. Restricts the drive
under test to seek operations
only.

ADDR ERROR
indicator

Indicates
that the
address
information
reeeived from the drive differs from the address requested, or that the address sync bit
was not received from the drive.

DATA ERROR
indicator

Indicates that the 8-bit data pattern received
from the drive differs from the pattern set in
the DATA PATTERN swi tches.

ERROR BYPASS
switches

ADDR

Address - If this switc'h is in
the up posi tion, it allows the
FTU to continue operating when
an address, s-c or S-M er ror
o C cur s • In th e down po sit ion,
an address error will stop the
FTU.

DATA

Data ~If this ,switch is in the
up posi tion, it allows the FTU
to continue operating when a
data error occurs.
In the
down po sit ion , a d a t a err 0 r
will 'stop the FTU.

RUN indicator

Indicates that the FTU is running or that the
RTZ switch (Return-to-Zero) is being actuated.
Five conditions will turn off the indicator.
o

Returning the RTZ switch to neutral,
provided RUN was not lit before the RTZ
operation

A valid (unbypassed) error

Actuating the STOP switch

Actuating the RESET switch

If the ready signal from the dr ive goes
low

A-IS

RTZ/RESET switch

START/STOP switch

A three-position momentary switch with center
"off."
RTZ

Clears HAR and CAR; clears the
drive's fault
register and
causes the drive to perform a
return-to-zero seek.
The RUN
1 ight on the FTU control panel
will be lit as long as this
switch is actuated to the RTZ
position.

Center

Neutral position.

RESET

Clears the error flip-flops in
the FTU and the dr ive.
This
switch must be actuated after a
valid error has occurred in order to be able to restart the
FTU.

A three-position momentary switch with center

"off."
START

Generates a pulse that starts
the FTU; turns on the RUN
i nd i cat 0 r •
An ex i s tin 9 err 0 r
condition must be cleared by
actuating the RESET switch
before START will have any effect.

Center

Neutral position.

STOP

Stops the FTU;
extinguishes
the RUN indicator.

UNIT SEL
indicator

Indicates that the unit number of the drive
under test ag rees wi th tha t set in the UNIT
NO. switches on the FTU, and that the tester
is receiving a plug valid signal from the
drive.

eLK ERROR
indicator

Indicates that a per iod of 200 nanoseconds has
expired wi thout a servo clock pulse from the
drive under test.

S-C ERROR

Indicates that the sector counter in the drive
under test does not agree with the sector
counter in the FTU.

indicator

A-16

S-M ERROR
indicator

Indicates that an incorrect number of sector
marks was received from the dr ive under test
between successive index marks.

WRT PROTECT
indicator

Ind cates the presence of a write-protect
sig al from the drive under test.

SEC 30/32
indicator

Ind cates whether
sec or mode.

SEEK ERROR
indicator

Indicates the presence of a seek error signal
from the drive under test.

FAULT
indicator

Indicates the presence of a
the drive under test.

ON CL
indicator

Indicates the p~esence of an on cylinder signal from the dr ive under test, or a pseudo
on-cylinder signal. generated by the FTU if in
maintenance mode.

UNIT READY
indicator

Indicates the presence of a ready signal.
This signal comes from the drive if the A and
B I/O cables are connected between .the dr ive
and the FTU.

DISPLAY
indicators

Refer to diagram shown for the
swi tch (Fig ure A-6).

DATA PATTERNS
switches

These switches permit setting the repetitive
a-bit pattern that is written in the data
field of the selected track dur ing a wr i te
operation. For read operations, the data read
from the track is compared with these switches
to check for the presence of a read error. A
one is ind icated when a swi tch is in the up
position, a zero whe~ in the down position.

CYLINDER ADDRESS
switches

These switches enter the binary value of the
cylinder address to which a seek is desired
and are used in conj unction wi th the ACCESS
MODE switch. A one is indicated when a switch
is in the up position; a zero when in the down
position.

FIXED/BOTH
MOVABLE switch

Not used.

A-17

the

drive is

in 30 or 32

fault signal from

DISPLAY SELECT

SEQ/MAN
swi tch

This switch determines the manner in which the
,head address is selected.
SEQ

Sequential - After performing a
wr i teo t rea dope rat ion, the
FT U inc rea se s the co un tin the
head address register by one
for each index mark. When in a
random operation, each access
increases the count by one.
When the count is maximum (19),
head zero is the' next head
selected and the incrementing
continues.

MAN

Manual - The FTU wi 11 sel ec t
the head address set in the
HEAD ADDRESS switches.

ADDR ERROR
test po int

This test point goes to
an address error occurs.

a logical zero

DATA ERROR
test po int

This test point goes to
when a data error occurs.

a logical zero

SECTOR MARK
test po int

This test point goes to a logical one when
the FTU receives a sector mark signal from the
drive under test.

ON CYL
test point

This test point will be a logical zero
the drive under test 1s on cylinder.

READ DATA
test po int

This test point reflects the binary value of
the serial data bits being received from the
drive under test during a read operation. The
test point is inoperative during maintenance
mode.

WRITE DATA
test po int

Th is test po int reflects the binar y val ue of
ser ial data bits being processed by the FTU
during a write operation.
The indication is
valid for any wri,te operation, even though the
FTtJ is in the maintenance mode.
The test
po;~nt~: ,rema i,ns, a :~log ical 9 d ur ing read oper ations.
","'

BITS 9-9
test points

These ten test points reflect the log ical value of the bus-out bits (BOB) delivered to the
dr ive under test via the A cable.
Log ically,
these bits' are present in the FTU's bus-out
multiplexer and are available at the test
point panel regardless of the operating mode
of the TB3A2.
For an interpretation of the
specific bus-out bits, see Table A-2.
A-1S

when

Table A-2
Bus-Out-Lines

Tag 1

Tag 2

PTU Test Points
Tag 3

Bit e l l

Write Gate - Enables write circuits
in drive unless drive is write-protected.

Bi t 1

Read Ga te - Enables read circui ts in
dr ive.

Bit 2

Servo Offset Plus - Offsets- the actuator from the nominal on cylinder position toward the spindle.

Bi t 3

Servo Offset Minus - Offsets the actuator from the nominal on cylinder
position away from the spindle.

Bit 4

Fa u 1 t e l ea r - Pu 1 se to c lea r the
fault summary flip-flop in the drive.

Bi t 5

Not used.

Bit 6

RTZ - Pulse that CBuses the drive
actuator to seek to track zero.

Bit 7

128

Data Strobe Early - -Enables the
dr ive' s PLO separator to strobe the
data at a time earlier than optimum.

Bit 8

256

Data Strobe Late Enables the
drive's PLO data separator to strobe
the data at a time later than optimum.

Bit 9

512

The three .tag bu!s lines define the operation to be performed by
the drive.
Tag 1 gates the cylinder address and initiates the
seek. Tag 2 gates the head addres.~- Ta9~ ~-is the control select
that gates the function to be performed •.

A-19

GNO test po int

This test point 1s a common ground point between the FTU logic board and the control panel.

W~IT~

This test point reflects: the logic level of
the 9.667 MHz write-clock signal that the FTU
sends to the drive under test during any write
operation.

CLK

'test point

READ CLK
test point

WRITE GATE
test point

READ GATE
test point

This test point reflect's thEf' rogie level of
the 9.667 MHz read-clock signal received from
the dr ive under test dur ing any read operation.
A read error forces the test point to
log ical zero.
A logical one at this point indicates the
presence of a write gate signa~ generated by
the FTU d ur ing any wr i te opera t ion.
A logical one at this test point indicates
the presence of a read 'gate signal generated
by the .FTU during any read operation.

CYL SELECT

This test point goes to a logical one when
the FTU sends a cylinder select signal (tag 1)
to the dr ive.

HEAD SELECT

This test point goes to a logical one when the
FTU sends a head select signal (tag 2) to the
drive.

test po in t

test po int

CONTROL SELECT
test po int

This test point goes to a log ical one when the
FTU sends a control select signal (tag 3) to
the drive.

A-20

Reader's Comments

RM05 DiSk Subsystem
Servk:e Manual

IK-ORMOS-SV-002

Vour comments and lUllestions will help us I. our continuous effort to Impro.e the quality and userulness or our
,..lieatlons.
'
. What is your lenera) reaction to this'manual? In your judlment is it complete, aCCUl ate, well organiz~d. well
written, etc.' Is it ~~y to use?
. ~.--

What faults or errors have you found in the manual? _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

Does this manual satisfy the need you think it was intended to satisfy? _ _ _ _ _ _ _ _ _ _ _ __
Does it satisfy your needs? _,_____________ Why? ______________________

Please send me the current copy of the Technical Documentation Catalog. which contains information on
the remainder of DIGITAL's technical documentation.
. .

Name ________._ _ _

____ Street __________________

Title _".,..,..________________ City _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __

Compa.nr.,-...~-,---__"""'-_ _ _ _ _ _ . State/C~untry ~_ _ _ _ _ _ _ _ _ _ __
Department
Zip

Additional copies of this document are available from:
Dilital Equipment Corporation
444 Whitney Street'
.
Northboro, Ma 0lS32
Attention: Communications Services (NR2/M 1S)
Customer Services Section
Order No. _ _ _ _E_K......;;;.O,.;;.R;.;.M.;;.;O~5...:.S:..;\;...'-O:.:O:.:2_ _ _ __

,~--

-.- - -'- - - - .0....··- - . . . . . . . . . -- - -.---

. .•. 8U8:'NISS'RIP,LY 'MAIL

D9foI' ~.c.,......
!ducetiottdt' .......
et.Y.fopmMf GtWI 'uMf"'itIf

3Cn Ifodcf'HMrCM BouIMwcJ South
Spring., Coforado' . "

ect'""